Use of mixed duplex oligonucleotides to effect localized genetic changes in plants

ABSTRACT

The invention concerns the use of duplex oligonucleotides about 25 to 30 base pairs to introduce site specific genetic alterations in plant cells. The oligonucleotides can be delivered by mechanical (biolistic) systems or by electrpoporation of plant protoplasts. Thereafter plants having the genetic alteration can be generated from the altered cells. In specific embodiments the invention concerns alteration in the gene that encode acid invertase, UDP-glucose pyrophosphorylase, polyphenol oxidase, O-methyl transferase, cinnamyl alcohol dehydrogenase, ACC synthase and ACC oxidase or etr-1 or a homolog of etr-1, and plants having isolated point mutations in such genes.

1. FIELD OF THE INVENTION

[0001] The field of the present invention relates to methods for the improvement of existing lines of plants and to the development of new lines having desired traits. The previously available methods of obtaining genetically altered plants by recombinant DNA technology enabled the introduction of preconstructed exogenous genes in random, atopic positions, so-called transgenes. In contrast the present invention allows the skilled practitioner to make a specific alteration of a specific pre-existing gene of a plant. The invention utilizes duplex oligonucleotides having a mixture of RNA-like nucleotides and DNA-like nucleotides to effect the alterations, hereafter “mixed duplex oligonucleotides” or MDON.

2. BACKGROUND TO THE INVENTION

[0002] 2.1 MDON and Their Use to Effect Specific Genetic Alterations

[0003] Mixed duplex oligonucleotides (MDON) and their use to effect genetic changes in eukaryotic cells are described in U.S. Pat. No. 5,565,350 to Kmiec (Kmiec I). Kmiec I discloses inter alia MDON having two strands, in which a first strand contains two segments of at least 8 RNA-like nucleotides that are separated by a third segment of from 4 to about 50 DNA-like nucleotides, termed an “interposed DNA segment.” The nucleotides of the first strand are base paired to DNA-like nucleotides of a second strand. The first and second strands are additionally linked by a segment of single stranded nucleotides so that the first and second strands are parts of a single oligonucleotide chain. Kmiec I further teaches a method for introducing specific genetic alterations into a target gene. According to Kmiec I, the sequences of the RNA segments are selected to be homologous, i.e., identical, to the sequence of a first and a second fragment of the target gene. The sequence of the interposed DNA segment is homologous with the sequence of the target gene between the first and second fragment except for a region of difference, termed the “heterologous region.” The heterologous region can effect an insertion or deletion, or can contain one or more bases that are mismatched with the sequence of target gene so as to effect a substitution. According to Kmiec I, the sequence of the target gene is altered as directed by the heterologous region, such that the target gene becomes homologous with the sequence of the MDON. Kmiec I specifically teaches that ribose and 2′-Omethylribose, i.e., 2′-methoxyribose, containing nucleotides can be used in MDON and that naturally-occurring deoxyribose-containing nucleotides can be used as DNA-like nucleotides.

[0004] U.S. patent application Ser. No. 08\664,487, filed Jun. 17, 1996, now U.S. Pat. No. 5,731,181 (Kmiec II) does specifically disclose the use of MDON to effect genetic changes in plant cells and discloses further examples of analogs and derivatives of RNA-like and DNA-like nucleotides that can be used to effect genetic changes in specific target genes.

[0005] Scientific publications disclosing uses of MDON having interposed DNA segments include Yoon, et al., 1996, Proc. Natl. Acad. Sci. 93:2071-2076 and Cole-Straus, A. et al., 1996, SCIENCE 273:1386-1389. The scientific publications disclose that rates of mutation as high as about one cell in ten can be obtained using liposomal mediated delivery. However, the scientific publications do not disclose that MDON can be used to make genetic changes in plant cells.

[0006] The present specification uses the term MDON, which should be understood to be synonymous with the terms “chimeric mutation vector,” “chimeric repair vector” and “chimeraplast” which are used elsewhere.

[0007] 2.2 Transgenic Plant Cells and the Generation of Plants from Transgenic Plant Cells

[0008] Of the techniques taught by Kmiec I and II for delivery of MDON into the target cell, the technique that is most applicable for use with plant cells is the electroporation of protoplasts. The regeneration of fertile plants from protoplast cultures has been reported for certain species of dicotyledonous plants, e.g., Nicotiana tobacum (tobacco), U.S. Pat. No. 5,231,019 and Fromm, M. E., et al., 1988, Nature 312, 791, and soybean variety Glycine max, WO 92/17598 to Widholm, J. M. However, despite the reports of isolated successes using non-transformed cells, Prioli, L. M., et al., Bio/technology 7, 589, Shillito, R. D., et al., 1989, Bio/Technology 7, 581, the regeneration of fertile monocotyledonous plants from transformed protoplast cultures is not regarded as obtainable with application of routine skill. Frequently, transformed protoplasts of monocotyledonous plants result in non-regenerable tissue or, if the tissue is regenerated the resultant plant is not fertile.

[0009] Other techniques to obtain transformed plant cells by introducing kilobase-sized plasmid DNA into plant cells having intact or partially intact cell walls have been developed. U.S. Pat. No. 4,945,050, U.S. Pat. No. 5,100,792 and U.S. Pat. No. 5,204,253 concern the delivery of plasmids into intact plant cells by adhering the plasmid to a microparticle that is ballistically propelled across the cell wall, hereafter “biolistically transformed” cell. For example U.S. Pat. No. 5,489,520 describes the regeneration of a fertile maize plant from a biolistically transformed cell. Other techniques for the introduction of plasmid DNA into suspensions of plant cells having intact cell walls include the use of silicon carbide fibers to pierce the cell wall, see U.S. Pat. No. 5,302,523 to Coffee R., and Dunwell, J. M.

[0010] A technique that allows for the electroporation of maize cells having a complex cell wall is reported in U.S. Pat. No. 5,384,253 to Krzyzek, Laursen and P. C. Anderson. The technique uses a combination of the enzymes endopectin lyase (E.C. 3.2.1.15) and endopolygalacturonase (E.C. 4.2.2.3) to generate transformation competent cells that can be more readily regenerated into fertile plants than true protoplasts. However, the technique is reported to be useful only for F1 cell lines from the cross of line A188×line B73.

3. SUMMARY OF THE INVENTION

[0011] The present invention provides new methods of use of the MDON that are particularly suitable for use in such plant cells.

[0012] Thus one aspect of the invention is techniques to adhere MDON to particles which can be projected through the cell wall to release the MDON within the cell in order to cause a mutation in a target gene of the plant cell. The mutations that can be introduced by this technique are mutations that confer a growth advantage to the mutated cells under appropriate conditions and mutations that cause a phenotype that can be detected by visual inspection. Such mutations are termed “selectable mutations.”

[0013] In a further embodiment the invention encompasses a method of introducing a mutation other than a selectable mutation into a target gene of a plant cell by a process which includes the steps of introducing a mixture of a first MDON that introduces a selectable mutation in the plant cell and a second MDON that causes the non-selectable mutation.

[0014] The invention further encompasses the culture of the cells mutated according to the foregoing embodiments of the invention so as to obtain a plant that produces seeds, henceforth a “fertile plant,” and the production of seeds and additional plants from such a fertile plant.

[0015] The invention further encompasses fertile plants having novel characteristics which can be produced by the methods of the invention.

4. DETAILED DESCRIPTION OF THE INVENTION

[0016] 4.1 Recombinagenic Oligonucleobases and Mixed Duplex OligoNucleotides

[0017] The invention can be practiced with MDON having the conformations and chemistries described in Kmiec I or in Kmiec II, which are hereby incorporated by reference. The MDON of Kmiec I and/or Kmiec II contain two complementary strands, one of which contains at least one segment of RNA-type nucleotides (an “RNA segment”) that are base paired to DNA-type nucleotides of the other strand.

[0018] Kmiec II discloses that purine and pyrimidine base-containing non-nucleotides can be substituted for nucleotides. Commonly assigned U.S. patent application Ser. No. 09/078,063, filed May 12, 1998, and Ser. No. 09/078,064, filed May 12, 1998, which are each hereby incorporated in their entirety, disclose additional molecules that can be used for the present invention. The term “recombinagenic oligonucleobase” is used herein to denote the molecules that can be used in the present invention. Recombinagenic oligonucleobases include MDON, non-nucleotide containing molecules taught in Kmiec II and the molecules taught in the above noted commonly assigned patent applications.

[0019] In a preferred embodiment the RNA-type nucleotides of the MDON are made Rnase resistant by having replacing the 2′-hydroxyl with a fluoro, chloro or bromo functionality or by placing a substituent on the 2′-O. Suitable substituents include the substituents taught by the Kmiec II, C₁₋₆ alkane. Alternative substituents include the substituents taught by U.S. Pat. No. 5,334,711 (Sproat) and the substituents taught by patent publications EP 629 387 and EP 679 657 (collectively, the Martin Applications), which are hereby incorporated by reference. As used herein a 2′-fluoro, chloro or bromo derivative of a ribonucleotide or a ribonucleotide having a 2′-OH substituted with a substituent described in the Martin Applications or Sproat is termed a “2′-Substituted Ribonucleotide.” As used herein the term “RNA-type nucleotide” means a 2′-hydroxyl or 2′-Substituted Nucleotide that is linked to other nucleotides of a MDON by an unsubstituted phosphodiester linkage or any of the non-natural linkages taught by Kmiec I or Kmiec II. As used herein the term “deoxyribo-type nucleotide” means a nucleotide having a 2′-H, which can be linked to other nucleotides of a MDON by an unsubstituted phosphodiester linkage or any of the non-natural linkages taught by Kmiec I or Kmiec II.

[0020] A particular embodiment of the invention comprises MDON that are linked solely by unsubstituted phosphodiester bonds. Alternatively embodiments comprise linkage by substituted phosphodiesters, phosphodiester derivatives and non-phosphorus-based linkages as taught by Kmiec II. A further particular embodiment comprises MDON wherein each RNA-type nucleotide is a 2′-Substituted Nucleotide. Particular preferred embodiments of 2′-Substituted Ribonucleotides are 2′-fluoro, 2′-methoxy, 2′-propyloxy, 2′-allyloxy, 2′-hydroxylethyloxy, 2′-methoxyethyloxy, 2′-fluoropropyloxy and 2′-trifluoropropyloxy substituted ribonucleotides. In more preferred embodiments of 2′-Substituted Ribonucleotides are 2′-fluoro, 2′-methoxy, 2′-methoxyethyloxy, and 2′-allyloxy substituted nucleotides. In one embodiment the MDON oligomer is linked by unsubstituted phosphodiester bonds.

[0021] Although MDON having only a single type of 2′-substituted RNA-type nucleotide are more conveniently synthesized, the invention can be practiced with MDON having two or more types of RNA-type nucleotides. The function of an RNA segment may not be affected by an interruption caused by the introduction of a deoxynucleotide between two RNA-type trinucleotides, accordingly, the term RNA segment encompasses such an “interrupted RNA segment.” An uninterrupted RNA segment is termed a contiguous RNA segment. In an alternative embodiment an RNA segment can contain alternating RNase-resistant and unsubstituted 2′-OH nucleotides. The MDON of the invention preferably have fewer than 100 nucleotides and more preferably fewer than 85 nucleotides, but more than 50 nucleotides. The first and second strands are Watson-Crick base paired. In one embodiment the strands of the MDON are covalently bonded by a linker, such as a single stranded hexa, penta or tetranucleotide so that the first and second strands are segments of a single oligonucleotide chain having a single 3′ and a single 5′ end. The 3′ and 5′ ends can be protected by the addition of a “hairpin cap” whereby the 3′ and 5′ terminal nucleotides are Watson-Crick paired to adjacent nucleotides. A second hairpin cap can, additionally, be placed at the junction between the first and second strands distant from the 3′ and 5′ ends, so that the Watson-Crick pairing between the first and second strands is stabilized.

[0022] The first and second strands contain two regions that are homologous with two fragments of the target gene, i.e., have the same sequence as the target gene. A homologous region contains the nucleotides of an RNA segment and may contain one or more DNA-type nucleotides of connecting DNA segment and may also contain DNA-type nucleotides that are not within the intervening DNA segment. The two regions of homology are separated by, and each is adjacent to, a region having a sequence that differs from the sequence of the target gene, termed a “heterologous region.” The heterologous region can contain one, two or three mismatched nucleotides. The mismatched nucleotides can be contiguous or alternatively can be separated by one or two nucleotides that are homologous with the target gene. Alternatively, the heterologous region can also contain an insertion or one, two, three or of five or fewer nucleotides. Alternatively, the sequence of the MDON may differ from the sequence of the target gene only by the deletion of one, two , three, or five or fewer nucleotides from the MDON. The length and position of the heterologous region is, in this case, deemed to be the length of the deletion, even though no nucleotides of the MDON are within the heterologous region. The distance between the fragments of the target gene that are complementary to the two homologous regions is identically the length of the heterologous region when a substitution or substitutions is intended. When the heterologous region contains an insertion, the homologous regions are thereby separated in the MDON farther than their complementary homologous fragments are in the gene, and the converse is applicable when the heterologous region encodes a deletion.

[0023] The RNA segments of the MDON are each a part of a homologous region, i.e., a region that is identical in sequence to a fragment of the target gene, which segments together preferably contain at least 13 RNA-type nucleotides and preferably from 16 to 25 RNA-type nucleotides or yet more preferably 18-22 RNA-type nucleotides or most preferably 20 nucleotides. In one embodiment, RNA segments of the homology regions are separated by and adjacent to, i.e., “connected by” an intervening DNA segment. In one embodiment, each nucleotide of the heterologous region is a nucleotide of the intervening DNA segment. An intervening DNA segment that contains the heterologous region of a MDON is termed a “mutator segment.” Commonly assigned U.S. patent application Ser. No. 09/078,063, filed May 12, 1998, and Ser. No. 09/078,064, filed May 12, 1998, disclose a type of duplex recombinagenic oligonucleobase in which a strand has a sequence that is identical to that of the target gene and only the sequence of the “complementary” strand contains a heterologous region. This configuration results in one or more mismatched bases or a “heteroduplex” structure. The heterologous region of the heteroduplex recombinagenic oligonucleobases that are useful in the present invention is located in the strand that contains the deoxynucleotides. In one embodiment, the heterologous region is located on the strand that contains the 5′ terminal nucleotide.

[0024] 4.2 The Location and Type of Mutation Introduced by a MDON

[0025] Frequently, the design of the MDON for use in plant cells must be modified from the designs taught in Kmiec I and II. In mammalian and yeast cells, the genetic alteration introduced by a MDON that differs from the target gene at one position is the replacement of the nucleotide in the target gene at the mismatched position by a nucleotide complementary to the nucleotide of the MDON at the mismatched position. By contrast, in plant cells there can be an alteration of the nucleotide one base 5′ to the mismatched position on the strand that is complementary to the strand that contains the DNA mutator segment. The nucleotide of the target gene is replaced by a nucleotide complementary to the nucleotide of the DNA mutator segment at the mismatched position. Consequently, the mutated target gene differs from the MDON at two positions.

[0026] The mutations introduced into the target gene by a MDON are located between the regions of the target gene that are homologous with the ribonucleotide portion of the homology regions of the MDON, henceforth the “RNA segments.” The specific mutation that is introduced depends upon the sequence of the heterologous region. An insertion or deletion in the target gene can be introduced by using a heterologous region that contains an insertion or deletion, respectively. A substitution in the target gene can be obtained by using a MDON having a mismatch in the heterologous region of the MDON. In the most frequent embodiments, the mismatch will convert the existing base of the target gene into the base that is complementary to the mismatched base of the MDON. The location of the substitution in the target gene can be either at the position that corresponds to the mismatch or, more frequently, the substitution will be located at the position on the target strand immediately 5′ to the position of the mismatch, i.e., complementary to the position of the MDON immediately 3′ of the mismatched base of the MDON.

[0027] The relative frequency of each location of the mismatch-caused substitution will be characteristic of a given gene and cell type. Thus, those skilled in the art will appreciate that a preliminary study to determine the location of substitutions in the gene of particular interest is generally indicated, when the location of the substitution is critical to the practice of the invention.

[0028] 4.3 The Delivery of MDON by Microcarriers and Microfibers

[0029] The use of metallic microcarriers (microspheres) for introducing large fragments of DNA into plant cells having cellulose cell walls by projectile penetration is well known to those skilled in the relevant art (henceforth biolistic delivery). U.S. Pat. No. 4,945,050, U.S. Pat. No. 5,100,792 and U.S. Pat. No. 5,204,253 concern general techniques for selecting microcarriers and devices for projecting them.

[0030] The conditions that are used to adhere DNA fragments to the microcarriers are not suitable for the use of MDON. The invention provides techniques for adhering sufficient amounts of MDON to the microcarrier so that biolistic delivery can be employed. In a suitable technique, ice cold microcarriers (60 mg/ml), MDON (60 mg/ml) 2.5 M CaCl₂ and 0.1 M spermidine are added in that order; the mixture gently agitated, e.g., by vortexing, for 10 min and allowed to stand at room temperature for 10 min whereupon the microcarriers are diluted in 5 volumes of ethanol, centrifuged and resuspended in 100% ethanol. Good results can be obtained with a concentration in the adhering solution of 8-10 μg/μl microcarriers, 14-17 μg/ml MDON, 1.1-1.4 M CaCl₂ and 18-22 mM spermidine. Optimal results were observed under the conditions of 8 μg/μl microcarriers, 16.5 μg/ml MDON, 1.3 M CaCl₂ and 21 mM spermidine.

[0031] MDON can also be introduced into plant cells for the practice of the invention using microfibers to penetrate the cell wall and cell membrane. U.S. Pat. No. 5,302,523 to Coffee et al. describes the use of 30×0.5 μm and 10×0.3 μm silicon carbide fibers to facilitate transformation of suspension maize cultures of Black Mexican Sweet. Any mechanical technique that can be used to introduce DNA for transformation of a plant cell using microfibers can be used to deliver MDON for transmutation.

[0032] A suitable technique for microfiber delivery of MDON is as follows. Sterile microfibers (2 μg) are suspended in 150 μl of plant culture medium containing about 10 μg of MDON. A suspension culture is allowed to settle and equal volumes of packed cells and the sterile fiber/MDON suspension are vortexed for 10 minutes and plated. Selective media are applied immediately or with a delay of up to about 120 hours as is appropriate for the particular trait.

[0033] The techniques that can be used to deliver MDON to transmute nuclear genes can also be used to cause transmutation of the genes of a plastid of a plant cell. Plastid transformation of higher plants by biolistic delivery of a plasmid followed by an illegitimate recombinatorial insertion of the plasmid is well known to those skilled in the art. Svab, Z., et al., 1990, Proc. Natl. Acad. Sci. 87, 8526-8530. The initial experiments showed rates of transformation that were between 10-fold and 100-fold less than the rate of nuclear transformation. Subsequent experiments showed that rates of plasmid transformation comparable to the rate of nuclear transformation could be achieved by use of a dominant selectable trait such as a bacterial aminoglycoside 3′-adenosyltransferase gene, which confers spectinomycin resistance. Svab, Z., & Maliga, P., 1993, Proc. Natl. Acad. Sci. 90, 913-917.

[0034] According to the invention MDON for the transmutation of plastid genes can be introduced into plastids by the same techniques as above. When the mutation desired to be introduced is a selectable mutation the MDON can be used alone. When the desired mutation is non-selectable the relevant MDON can be introduced along with a MDON that introduces a selectable plastid mutation, e.g., a mutation in the psbA gene that confers triazine resistance, or in combination with a linear or circular plasmid that confers a selectable trait.

[0035] The foregoing techniques can be adapted for use with recombinagenic oligonucleobases other than MDON.

[0036] 4.4 Protoplast Electroporation

[0037] In an alternative embodiment the recombinagenic oligonucleobase can be delivered to the plant cell by electroporation of a protoplast derived from a plant part. The protoplasts are formed by enzymatic treatment of a plant part, particularly a leaf, according to techniques well known to those skilled in the art. See, e.g., Gallois et al., 1996, in Methods in Molecular Biology 55, 89-107 (Humana Press, Totowa, N.J.). The protoplasts need not be cultured in growth media prior to electroporation.

[0038] Suitable conditions for electroporation are 3×10⁵ protoplasts in a total volume of 0.3 ml with a concentration of MDON of between 0.6-4 μg/mL.

[0039] 4.5 The Introduction of Mutations

[0040] The invention can be used to effect genetic changes, herein “transmutate,” in plant cells. In an embodiment the plant cells have cell walls, i.e., are other than protoplasts.

[0041] The use of MDON to transmutate plant cells can be facilitated by co-introducing a trait that allows for the ready differentiation and separation of cells (hereafter “selection”) into which MDON have been introduced from those that have not. In one embodiment of the invention the selection is performed by forming a mixture of MDON and a plasmid that causes the transient expression of a gene that confers a selectable trait, i.e., one that permits survival under certain conditions, e.g., a kanamycin resistance gene. Under these circumstances elimination of cells lacking the selectable trait removes the cells into which MDON were not introduced. The use of a transient expression plasmid to introduce the selectable trait allows for the successive introduction of multiple genetic changes into a plant cell by repeatedly using a single standardized selection protocol.

[0042] In an alternative embodiment transmutation can be used to introduce a selectable trait. A mixture of a first MDON that causes a selectable mutation in a first target gene and a second MDON that causes a non-selectable mutation in a second target gene is prepared. According to the invention, at least about 1% of the cells having the selectable mutation will be found to also contain a mutation in the second target gene that was introduced by the second MDON. More frequently at least about 10% of the cells having the selectable mutation will be found to also contain a mutation in the second target gene.

[0043] One use of this embodiment of the invention is the investigation of the function of a gene-of-interest. A mixture is provided of a MDON that causes a selectable mutation and a MDON that causes a mutation that would be expected to “knock-out” the gene-of-interest, e.g., the insertion of a stop codon or a frameshift mutation. Cells in which one or more copies of the gene-of-interest have been knocked out can be recovered from the population having the selectable mutation. Such cells can be regenerated into a plant so that the function of the gene-of-interest can be determined.

[0044] A selectable trait can be caused by any mutation that causes a phenotypic change that can produce a selective growth advantage under the appropriate selective conditions or a phenotypic change that can be readily observed, such as change in color of the plant cells growing in a callus. The selectable trait can itself be a desirable traits, e.g., herbicide resistance, or the selectable trait can be used merely to facilitate the isolation of plants having a non-selectable trait that was introduced by transmutation. A desired nonselectable trait can be introduced into a cell by using a mixture of the MDON that causes the desired mutation and the MDON that causes the selectable mutation, followed by culture under the selecting conditions. Selection according to this scheme has the advantage of ensuring that each selected cell not only received the mixture of MDONs, but also that the cell which received the mixture was then susceptible to transmutation by a MDON.

[0045] A mutation that causes a lethal phenotypic change under the appropriate conditions, termed a negatively selectable mutation, can also be used in the present invention. Such mutations cause negatively selectable traits. Negatively selectable traits can be selected by making replica plates of the transmutated cells, selecting one of the replicas and recovering the transmutated cell having the desired property from the non-selected replica.

[0046] 4.6 Specific Genes That Can Be Transmutated to Create Selectable Traits

[0047] In one embodiment of the invention a MDON is used to introduce a mutation into an Acetolactate synthase (ALS) gene, which is also termed the aceto-hydroxy amino acid synthase (AHAS) gene. Sulfonylurea herbicides and imidazoline herbicides are inhibitors of the wild type ALS enzymes. Dominant mutations that render plants resistant to the actions of sulfonylureas and imidazolines have been described. See U.S. Pat. Nos. 5,013,659 and 5,378,824 (Bedbrook) and Rajasekaran K., et al., 1996, Mol. Breeding 2, 307-319 (Rajasekaran). Bedbrook at Table 2 describes several mutations (hereafter, a “Bedbrook Mutation”) that were found to render yeast ALS enzymes resistant to sulfonylurea herbicides. Bedbrook states that each of the Bedbrook mutations makes a plant resistant to sulfonylurea and imidazoline herbicides when introduced into a plant ALS gene. It is understood that in most plants the gene encoding ALS has been duplicated. A mutation can be introduced into any allele of either ALS gene.

[0048] Three of the Bedbrook mutations were, in fact, shown to confer herbicide resistance in a plant, namely the substitutions Pro→Ala¹⁹⁷, Ala→Asp²⁰⁵ and Trp→Leu⁵⁹¹. Rajasekaran reports that mutations Trp→Ser⁵⁹¹ caused resistance to sulfonylurea and imidazoline and that Ser→Asn⁶⁶⁰ caused resistance to imidazoline herbicides. The results of Rajasekaran are reported herein using the sequence numbering of Bedbrook. Those skilled in the art will understand that the ALS genes of different plants are of unequal lengths. For clarity, a numbering system is used in which homologous positions are designated by the same position number in each species. Thus, the designated position of a mutation is determined by the sequence that surrounds it. For example, the mutation Trp→Ser⁵⁹¹ of Rajasekaran is at residue 563 of the cotton ALS gene but is designated as position 591 of Bedbrook because the mutated Trp is surrounded by the sequence that surrounds Trp⁵⁹¹ in Table 2 of Bedbrook. According to the invention any substitution for the naturally occurring amino and at position 660 or one of the positions listed in Table 2 of Bedbrook, which is hereby incorporated by reference, can be used to make a selectable mutation in the ALS gene of a plant.

[0049] In a further embodiment of the invention the selectable mutation can be a mutation in the chloroplast gene psbA that encodes the D1 subunit of photosystem II, see Hirschberg, J., et al., 1984, Z. Naturforsch. 39, 412-420 and Ohad, N., & Hirschberg, J., The Plant Cell 4, 273-282. Hirschberg et al. reports that the mutation Ser→Gly²⁶⁴ results in resistance to triazine herbicides, e.g., 2-Cl-4-ethylamino-6-isopropylamino-s-triazine (Atrazine). Other mutations in the psbA gene that cause Atrazine herbicide resistance are described in Erickson J. M., et al., 1989, Plant Cell 1, 361-371, (hereafter an “Erickson mutation”), which is hereby incorporated by reference. The use of the selectable trait caused by an Erickson mutation is preferred when it is desired to introduce a second new trait into a chloroplast.

[0050] The scientific literature contains further reports of other mutations that produce selectable traits. Ghislain M., et al., 1995, The Plant Journal 8, 733-743, describes a Asn→Ile¹⁰⁴ mutation in the Nicotiana sylvestris dihydrodipicolinate synthase (DHDPS, EC 4.2.1.52) gene that results in resistance to S-(2-aminoethyl)L-cysteine. Mourad, G., & King, J., 1995, Plant Physiology 109, 43-52 describes a mutation in the threonine dehydratase of Arabidopsis thaliana that results in resistance to L-O-methylthreonine. Nelson, J. A. E., et al., 1994, Mol. Cell. Biol. 14, 4011-4019 describes the substitution of the C-terminal Leu of the S14/rp59 ribosomal protein by Pro, which causes resistance to the translational inhibitors crytopluerine and emetine. In further embodiments of the invention, each of the foregoing mutations can be used to create a selectable trait. Each of Ghislain, Mourad and Nelson are hereby incorporated by reference.

[0051] 4.7 Genes That Can Be Mutated to Create Desirable Non-selectable Traits

EXAMPLE 1 Male Sterility

[0052] Certain commercially grown plants are routinely grown from hybrid seed including corn (maize, Zea maize), tomatoes and most other vegetables. The production of hybrid seed requires that plants of one purebred line be pollinated only by pollen from another purebred line, i.e., that there be no self pollination. The removal of the pollen-producing organs from the purebred parental plants is a laborious and expensive process. Therefore, a mutation that induces male-sterility i.e., suppresses pollen production or function, would obviate the need for such process.

[0053] Several genes have been identified that are necessary for the maturation or function of pollen but are not essential for other processes of the plant. Chalcone synthase (chs) is the key enzyme in the synthesis of flavonoids, which are pigments found in flowers and pollen. Inhibition of chs by the introduction of a chs antisense expressing gene in the petunia results in male sterility of the plant. Van der Meer, I. M., et al., 1992, The Plant Cell 4, 253-262. There is a family of chs genes in most plants. See, e.g., Koes, R. E., et al., 1989, Plant Mol. Biol. 12, 213-226. Likewise disruption of the chalcone synthase gene in maize by insertion of a transposable element results in male sterility. Coe, E. H., J. Hered. 72, 318-320. The structure of maize chalcone synthase and a duplicate gene, whp, is given in Franken, P., et al., 1991, EMBO J. 10, 2605-2612. Typically in plants each member of a multigene family is expressed only in a limited range of tissues. Accordingly, the present embodiment of the invention requires that in species having multiple copies of chalcone synthase genes, the particular chs gene or genes expressed in the anthers be identified and interrupted by introduction of a frameshift, and one or more in-frame termination codons or by interruption of the promoter.

[0054] A second gene that has been identified as essential for the production of pollen is termed Lat52 in tomato. Muschietti, J., et al., 1994, The Plant Journal 6, 321-338. LAT52 is a secreted glycoprotein that is related to a trypsin inhibitor. Homologs of Lat52 have been identified in maize (termed Zm13, Hanson D. D., et al., 1989 Plant Cell 1, 173-179; Twell D., et al., 1989, Mol. Gen. Genet. 217, 240-245), rice (termed Ps1, Zou J., et al., 1994 Am. J. Bot. 81, 552-561 and olive (termed Ole e I, Villalba, M., et al., 1993, Eur. J. Biochem. 276, 863-869). Accordingly, the present embodiment of the invention provides for a method of obtaining male sterility by the interruption of the Lat52/Zm13 gene or its homologs by the introduction of a frameshift, one or more in-frame termination codons or by interruption of the promoter.

[0055] A third gene that has been identified as essential for the production of pollen is the gene that encodes phenylalanine ammonium lyase (PAL, EC 4.3.1.5). PAL is an essential enzyme in the production of both phenylpropanoids and flavonoids. Because phenylpropanoids are a precursor to lignins, which can be an essential for the resistance to disease in the preferred embodiment a PAL isozyme that is expressed only in the anther is identified and interrupted to obtain male sterility.

EXAMPLE 2 Alteration of Carbohydrate Metabolism of Tubers

[0056] Once harvested, potato tubers are subject to disease, shrinkage and sprouting during storage. To avoid these losses the storage temperature is reduced to 35-40° F. However, at reduced temperatures, the starch in the tubers undergoes conversion to sugar, termed “cold sweetening”, which reduces the commercial and nutritional value of the tuber. Two enzymes are critical for the cold sweetening process: acid invertase and UDP-glucose pyrophosphorylase. Zrenner, R., et al., 1996, Planta 198, 246-252 and Spychalla, J. P., et al., 1994, J. Plant Physiol. 144, 444-453, respectively. The sequence of potato acid invertase is found in EMBL database Accession No. X70368 (SEQ ID NO. 1) and the sequence of the potato UDP Glucose pyrophosphorylase is reported be Katsube, T. et al., 1991, Biochem. 30, 8546-8551. Accordingly, the present embodiment of the invention provides for a method of preventing cold sweetening by the interruption of the acid invertase or the UDP glucose phosphorylase gene by introduction of a frameshift, one or more in-frame termination codons or by interruption of the promoter.

EXAMPLE 3 Reduction in Post Harvest Browning Due to PPO

[0057] Polyphenol oxidase (PPO) is the major cause of enzymatic browning in higher plants. PPO catalyzes the conversion of monophenols to o-diphenols and of o-dihydroxyphenols to o-quinones. The quinone products then polymerize and react with amino acid groups in the cellular proteins, which results in discoloration. The problem of PPO induced browning is routinely addressed by the addition of sulfites to the foods, which has been found to be associated with some possible health risk and consumer aversion. PPO normally functions in the defense of the plant to pathogens or insect pests and, hence, is not essential to the viability of the plant. Accordingly, the present embodiment of the invention provides for a method of preventing enzymatic browning by the interruption of the PPO gene by introduction of a frameshift, one or more in-frame termination codons or by interruption of the promoter in apple, grape, avocado, pear and banana.

[0058] The number of PPO genes in the genome of a plant is variable; in tomatoes and potatoes PPO forms a multigene family. Newman, S. M., et al., 1993, Plant Mol. Biol. 21, 1035-1051, Hunt M. D., et al., 1993, Plant Mol. Biol. 21, 59-68; Thygesen, P. W., et al., 1995, Plant Physiol. 109, 525-531. The grape contains only a single PPO gene. Dry, I. B., et al., 1994, Plant Mol. Biol., 26, 495-502. When the plant species of interest contains multiple copies of PPO genes it is essential that the PPO gene that is normally expressed in the commercial product be interrupted. For example, only one PPO gene is expressed in potatoes of harvestable size, which gene is termed POT32 and its sequence is deposited in GENBANK accession No. U22921 (SEQ ID NO. 2), which sequence is incorporated by reference. The other potato PPO isozymes have been sequenced and the sequences deposited so that one skilled in the art can design a MDON that specifically inactivates POT32.

EXAMPLE 4 Reduction of Lignin in Forage Crops and Wood Pulp

[0059] Lignin is a complex heterogeneous aromatic polymer, which waterproofs higher plants and strengthens their cell walls. Lignin arises from the random polymerization of free radicals of phenylpropanoid monolignins. Lignins pose a serious problem for the paper industry because their removal from wood pulp involves both monetary and environmental costs. Similarly, the lignin content of forage crops limits their digestibility by ruminants. Indeed, naturally occurring mutations, termed “brown mid-rib” in sorghum, Porter, K S, et al., 1978, Crop Science 18, 205-218, and maize, Lechtenberg, V. L., et al., 1972, Agron. J. 64, 657-660, have been identified as having reduced lignin content and tested as feed for cattle.

[0060] The brown mid-rib mutation in maize involves the O-methyl transferase gene. Vignol, F., et al., 1995, Plant Cell 7, 407-416. The O-methyltransferase genes of a number of plant species have been cloned: Burgos, R. C., et al., 1991, Plant Mol. Biol. 17, 1203-1215 (aspen); Gowri, G., et al., 1991, Plant Physiol. 97, 7-14 (alfalfa, Medicago sativa) and Jaeck, F., et al., 1992, Mol. Plant-Microbe Interact. 4, 294-300 (tobacco) (SEQ ID No. 3 and SEQ ID No. 4). Thus, one aspect of the present embodiment is the interruption of the O-methyltransferase gene to reproduce a brown mid-rib phenotype in any cultivar of maize or sorghum and in other species of forage crops and in plants intended for the manufacture of wood pulp.

[0061] A second gene that is involved in lignin production is the cinnamyl alcohol dehydrogenase (CAD) gene, which has been cloned in tobacco. Knight, M. E., 1992, Plant Mol. Biol. 19, 793-801 (SEQ ID No. 5 and SEQ ID No. 6). Transgenic tobacco plants making a CAD antisense transcript have reduced levels of CAD and also make a lignin that is more readily extractable, apparently due to an increase in the ratio of syringyl to guaiacyl monomers and to the increased incorporation of aldehyde monomers relative to alcohol residues. Halpin, C., et al., 1994, The Plant Journal 6, 339-350. Accordingly, an embodiment of the invention is the interruption of the CAD gene of forage crops such as alfalfa, maize, sorghum and soybean and of paper pulp trees such as short-leaf pine (Pinus echinata) long-leaf pine (Pinus palustris) slash pine (Pinus elliottii), loblolly pine (Pinus taeda), yellow-poplar (Liriodendron tulipifera) and cotton wood (Populus sp.) by introduction of a frameshift, one or more in-frame termination codons or by interruption of the promoter.

EXAMPLE 5 The Reduction in Unsaturated and Polyunsaturated Lipids in Oil Seeds

[0062] The presence of unsaturated fatty acids, e.g., oleic acid, and polyunsaturated fatty acids, e.g., linoleic and linolenic acids, in vegetable oil from oil seeds such as rape, peanut, sunflower and soybean causes the oils to oxidize, on prolonged storage and at high temperatures. Consequently, vegetable oil is frequently hydrogenated. However, chemical hydrogenation causes transhydrogenation, which produces non-naturally occurring stereo-isomers, which are believed to be a health risk.

[0063] Fatty acid synthesis proceeds by the synthesis of the saturated fatty acid on an acyl carrier protein (ACP) followed by the action of desaturases that remove the hydrogen pairs. Consequently, it would be desirable to inhibit the activity of these desaturase enzymes in oil seeds.

[0064] The first enzyme in the synthesis of oleic acid is stearoyl-ACP desaturase (EC 1.14.99.6). The stearoyl-ACP desaturases from safflower and castor bean have been cloned and sequenced. Thompson, G. A., et al., 1991, Proc. Natl. Acad. Sci. 88, 2578-2582 (SEQ ID No. 7); Shanklin, J., & Somerville, C., 1991, Proc. Natl. Acad. Sci. 88, 2510-2514 (SEQ ID No. 8); Knutzon, D. S., et al., 1991, Plant Physiology 96, 344-345. Accordingly, one embodiment of the present invention is the interruption of the stearoyl-ACP desaturase gene of oil seed crops such as soybean, safflower, sunflower, soy, maize and rape by introduction of a frameshift, one or more in-frame termination codons or by interruption of the promoter.

[0065] A second enzyme that can be interrupted according to the present invention is ω-3 fatty acid desaturase (ω-3 FAD) the enzyme that converts linoleic acid, a diene, to linolenic acid, a triene. There are two ω-3 FAD isozymes in Arabidopsis thaliana and, those skilled in the art expect, in most other plants. One isozyme is specific for plastids and is the relevant isozyme for the synthesis of the storage oils of seeds. The other is microsome specific. The cloning of the Arabidopsis thaliana plastid ω-3 FAD is reported by Iba., K. et al., 1993, J. Biol. Chem. 268, 24099-24105 (SEQ ID No. 9). Accordingly an embodiment of the invention is the interruption of the plastid ω-3 FAD gene of oil seed crops such as soybean, safflower, sunflower, soy, maize and rape by introduction of a frameshift, an in-frame termination codon or by interruption of the promoter.

EXAMPLE 6 Inactivation of S Alleles to Permit Inbred Lines

[0066] Certain plant species have developed a mechanism to prevent self-fertilization. In these species, e.g., wheat and rice, there is a locus, termed S, which has multiple alleles. A plant that expresses an S allele cannot be fertilized by pollen expressing the same S allele. Lee, H-K., et al., 1994, Nature 367, 560-563; Murfett, J., et al., 1994, Nature 367, 563. The product of the S locus is an RNase. McClure, B. A., et al., 1989, Nature 342, 955-957. The product of the S locus is not essential for the plant. Accordingly, an embodiment of the invention is the interruption of genes of the S locus to permit the inbreeding of the plant by introduction of a frameshift, one or more in-frame termination codons or by interruption of the promoter.

EXAMPLE 7 Ethylene Insensitivity

[0067] Ethylene is a gaseous plant hormone that is involved in plant growth and development. An unwanted aspect of ethylene's action is the over-ripening of fruit, vegetables and the wilting of flowers that results in rotting and loss. The ethylene receptor of Arabidopsis thaliana has been cloned and is termed ETR-1. Chang, C., et al., 1993, Science 262, 539-544 (SEQ ID No. 10). A mutant, Cys→Tyr⁶⁵, results in a dominant insensitivity to ethylene. Transgenic tomato plants expressing the Arabidopsis thaliana mutant ETR-1 also showed an insensitivity to ethylene, indicating that the Cys→Tyr⁶⁵ mutation would be a dominant suppressor of ethylene action in most plant species. Accordingly one aspect of the present embodiment of the invention is the insertion of the Cys→Tyr⁶⁵ mutation into the ETR-1 gene so as to extend the life span of the mutated fruit vegetable or flower.

[0068] In a further aspect of the present embodiment, the preservation of the fruit or flower can be achieved by interrupting one of the genes that encode the enzymes for ethylene synthesis: namely 1-aminocyclopropane-1-carboxylic acid synthase (ACC synthase) and ACC oxidase. For this embodiment of the invention the amount of ethylene synthesis can be eliminated entirely, so that ripening is produced by exogenous ethylene or some amount of ethylene production can be retained so that the fruit ripens spontaneously, but a has a prolonged storage life. Accordingly, it is anticipated that the interruption of one allele of either the ACC synthase or the ACC oxidase gene can result in an useful reduction in the level of ethylene synthesis. Alternatively, the invention provides for the interruption of one allele along with the introduction of a mutation that results in a partial loss of activity in the uninterrupted allele.

[0069] The sequences of the Arabidopsis thaliana ACC synthase and ACC oxidase genes are reported in Abel., S., et al., 1995, J. Biol. Chem. 270, 19093-19099 (SEQ ID No. 12) and Gomez-Lim, M. A., et al., 1993, Gene 134,217-221 (SEQ ID No. 11), respectively, which are incorporated by reference in their entirety.

EXAMPLE 8 Reversion of Kanamycin Resistance

[0070] Recombinant DNA technology in plants allows for the introduction of genes from one species of plant and bacterial genes into a second species of plant. For example, Kinney, A. J., 1996, Nature Biotech. 14, 946, describes the introduction of a bay laural ACP-thioesterase gene into the rape seed to obtain a vegetable oil rich in lauric acid. Such transgenic plants are normally constructed using an antibiotic resistance gene, e.g., kanamycin resistance, which is coinserted into the transgenic plant as a selectable trait. The resultant transgenic plant continues to express the antibiotic resistance gene, which could result in large amounts of the resistance product and the gene entering the food supply and/or the environment, which introduction may represent an environmental or health risk. An embodiment of the invention obviates the risk by providing for the interruption of the kanamycin gene by introduction of a frameshift, one or more in-frame termination codons or by interruption of the promoter.

EXAMPLE 9 Modification of Storage Protein Amino Acid Content

[0071] Seeds and tubers contain a family of major storage proteins, e.g., patatins in potato and zeins in maize. The amino acid composition of such storage proteins is often poorly suited to the needs of the human and animals that depend on these crops, e.g., corn is deficient in lysine and methionine and potato is deficient in methionine. Accordingly, one embodiment of the invention is the mutation of a storage protein of a food crop to increase the amount of low abundance amino acids. Patatins are encoded by a multigene family which are characterized in Mignery, G. A., et al., 1988, Gene 62, 27-44, and the structure of zeins is reported by Marks, M. D., et al., 1985, J. Biol. Chem. 260, 16451459, both of which are hereby incorporated by reference. Alternatively, the anticodon of a methionine or lysine specific tRNA can be mutated to that of a more common amino acid.

EXAMPLE 10 The Use of MDON to Determine the Function of a Gene

[0072] The presently available techniques for the cloning and sequencing of tissue specific cDNAs allow those skilled in the art to obtain readily the sequences of many genes. There is a relative paucity of techniques for determining the function of these genes. In one embodiment of the invention, MDON are designed to introduce frameshilft or stop codons into the gene encoding a cDNA of unknown function. This allows for the specific interruption of the gene. Plants having such specific “knock-outs” can be grown and the effects of the knock-out can be observed in order to investigate the function of the unknown gene.

[0073] 4.8 Fertile Plants of the Invention

[0074] The invention encompasses a fertile plant having an isolated selectable point mutation, which isolated selectable mutation is not a rare polymorphism, i.e., would not be found in population of about 10,000 individuals. As used herein a point mutation is mutation that is a substitution of not more than six contiguous nucleotides, preferably not more than three and more preferably one nucleotide or a deletion or insertion from one to five nucleotides and preferably of one or two nucleotides. As used herein an isolated mutation is a mutation which is not closely linked genetically to any other mutation, wherein it is understood that mutations that are greater than 100 Kb and preferably greater than 40 Kb and more preferably greater than 23 Kb are not closely linked.

BIOLISTIC WORKING EXAMPLES

[0075] In the following working examples the media and protocols found in Gelvin, S. B., et al., (eds) 1991, PLANT MOLECULAR BIOLOGY MANUAL (Kluwer Acad. Pub.) were followed. Gold particles were coated with MDON according the following protocol. The microprojectiles are first prepared for coating, then immediately coated with the chimeraplast. To prepare the microprojectiles, suspend 60 mg of gold particles in 1 ml of 100% ethanol (see Note 4). Sonicate the suspension for three, 30 s bursts to disperse the particles. Centrifuge at 12,000 ×g for 30 s, discard supernatant. Add 1 ml of 100% ethanol, vortex for 15 s, centrifuge at 12,000 ×g for 5 min, then discard the supernatant. A 25 μl suspension of washed gold particles (1.0 μm diameter, 60 mg/ml) in H₂O are slowly vortexed, to which 40 μl MDON (50 μg/ml), 75 μl of 2.5 M CaCl₂, 75 μl 0.1M spermidine are sequentially added. All solutions are ice cold. The completed mixture is vortexed for a further 10 min and the particles are allowed to settle at room temperature for a further 10 min. The pellet is washed in 100% EtOH and resuspended in 50 μl. of absolute ethanol. Biolistic delivery is performed using a Biorad Biolistic gun with the following settings: tank pressure 1100 psi, rupture disks ×2 breaking at 900 psi, particle suspension volume 5 μl.

[0076] NT-1 (Tobacco), a Dicot Cell Suspension:

[0077] Lawns of NT-1 of approximately 5 cm diameter, containing 5 million cells, were grown for 3 days on standard media at 28° C. Gold particles were coated with ALS-1 or ALS-2 and were shot as above. The cells were cultured a further 2.5 days, suspended and transferred to solid medium supplemented with 15-50 ppb chlorosulfuron (GLEAM™). Resistant colonies emerged after 7-14 days.

[0078] The sequences of the MDON used are as follows: (The nucleotides not homologous with the target gene are underlined and bold. Lower case letters denote 2′-Omethyl ribonucleotides.) ALS-1  TGCGCG-guccaguucaCG T TGcauccaacuaT (SEQ ID No. 13) T                                 T T                                 T  TCGCGC CAGGTCAAGTGC A ACGTAGGATGATT      3′ 5′ ALS-2  TGCGCG-guccaguucaCG A TGcauccaacuaT (SEQ ID No. 14) T                                 T T                                 T  TCGCGC CAGGTCAAGTGC T ACGTAGGATGATT      3′ 5′

[0079] ALS-1 and ALS-2 have single base mismatches with the ALS gene at the second nucleotide of the Pro¹⁹⁷ (CCA) codon: ALS-1 is CAA and ALS-2 is CTA. Following PCR amplfication and sequencing of the gene of the ALS-1 and ALS-2 transmutated, resistant cell lines, a mutation was in the targeted codon which was found to be Thr (ACA) and Ser (TCA), respectively. The observed mutation was shifted one nucleotide 5′ of the location that would have been expected based on the action of MDON in mammalian cells on the coding strand and one nucleotide 3′ of the expected location on the non-coding strand. A total of 3 ALS-1 and 5 ALS-2 transmutants having these mutations were identified. No resistant calli were obtained from ALS-1 DNA treated cells.

[0080] For selection of chlorsulfuron resistant cells, cells were transferred from each bombarded plate to 15 ml containing 5 ml of liquid CSM 2 d after bombardment. The tubes were inverted several times to disperse cell clumps. The cells were then transferred to solidified CSM medium containing 15 ppb chorsulfuron (Dupont, Wilmington, Del.). After approximately 3-5 wk, actively growing cells (raised, light colored colonies) are selected and transferred to solidified CSM containing 50 ppb chlorsulfuron. Three to four weeks later, actively growing cells are selected, then transferred to solidified CSM containing 200 ppb chlorsulfuron. Cells that survive this treatment are then analyzed.

[0081] Media

[0082] 1. NT-1 cell suspension medium (CSM): Murashige and Skoog salts (Gibco BRL, Grand Island, N.Y.), 500 mg/l MES, 1 mg/l thiamine, 100 mg/l myoinositol, 180 mg/l KH₂PO₄, 2.21 mg/L 2,4-diclorophenoxyacetic acid (2,4-D), 30 g/L sucrose. Adjust pH to 5.7 with 1M KOH or HCl and autoclave. For solidified medium add 8 g/l Agar-agar (Sigma, St. Louis, Mo.) prior to autoclaving.

[0083] 2. Plating out medium (POM): 80% (v/v) CSM, 0.3M mannitol, 20% (v/v) supernatant from the initial centrifugation of the NT-1 cell suspension prior to protoplast isolation.

[0084] Tobacco Leaf, a Dicot:

[0085]Nicotiana tabacum v. Samsun leaf disks were co-transformed by Agrobacterium tumefaciens LBA 4404 harboring bin 19-derived plasmids containing a nptll expression cassette containing two genes: a gene for kanamycin resistance and one of two mutants of a gene encoding a Green Fluorescence Protein (GFP, Chui, W., 1996, Current Biol. 6, 325-330). Neither mutant GFP gene produces a GFP product. The mutants contain either a G→T substitution in the sixth codon resulting in a stop codon or a deletion of one nucleotide at the same position, which are termed, respectively, G-stop and G-Δ. After culture on selective MS 104 medium, leaves were recovered and the presence of a GFP gene confirmed by northern blot. Sequence of first eight codons of GFP: (SEQ ID No. 15) GFP ATG GTG AGC AAG GGC GAG GAG CTG (SEQ ID No. 16) C-stop -------------------T----------- (SEQ ID No. 17) G-Δ --------------------AGG AGC TGT

[0086] The sequences of the MDON used were as follows: (The nucleotides not homologous with G-stop are underlined and bold. Lower case letters denote 2′-Omethyl ribonucleotides.) GFP-1  TGCGCG-cacucguuccCG C TCcucgacaaguT (SEQ ID No. 18) T                                 T T                                 T  TCGCGC GTGAGCAAGGGC G AGGAGCTGTTCAT       3′ 5′ GFP-2  TGCGCG-acucguucccGA G CCucgacaagugT (SEQ ID NO. 19) T                                 T T                                 T  TCGCGC TGAGCAAGGGCT C GGAGCTGTTCACT

[0087] Leaf disks of the G-stop and G-Δ transgenic plants were incubated on MS 104 selective media and G-1 or G-1 introduced biolistically by two successive deliveries as above. Approximately 10 days after the introduction of the MDON, calli exhibiting GFP-like fluorescence were seen in the G-1 and G-2 treated cultures of both the G-stop and G-Δ leaf disks. Larger and more rapidly growing callusing pieces were subdivided by scalpel to obtain green fluorescent cell-enriched calli. The fluorescent phenotype remained stable for the total period of observation, about 30 days. The presence of green fluorescent cells in the G-1 treated G-stop culture indicates that G-1 does not cause mutations exclusively one base 5′ of the mismatched nucleotide.

[0088] Green fluorescence was observed using a standard FITC filter set using an IMT-2 Olympus microscope.

ELECTROPORATION WORKING EXAMPLE Conversion of GFP in Tobacco Mesophyll Protoplasts

[0089] Plant Material

[0090] 1. Tobacco plant transformant (Delta6) harboring a deletion mutant of GFP.

[0091] 2. Leaves were harvested from 5 to 6-week-old in vitro-grown plantlets

[0092] Protoplast Isolation

[0093] 1. Basically followed the procedure of Gallois, et al., 1996, Electroporation of tobacco leaf protoplasts using plasmid DNA or total genomic DNA. Methods in Molecular Biology, Vol. 55: Plant Cell Electroporation and Electrofusion Protocols Edited by: J. A. Nickoloff Humana Press Inc., Totowa, N.J. pp. 89-107.

[0094] 2. Enzyme solution: 1.2% cellulase R-10 “Onozuka” (Karlan, Santa Rosa, Calif.), 0.8% macerozyme R-10 (Karlan, Santa Rosa, Calif.), 90 g/l mannitol, 10 mM MES, filter sterilize, store in 10 ml aliquots at −20° C.

[0095] 3. Leaves were cut from the mid-vein out every 1-2 mm. They were then placed abaxial side down in contact with 10 ml of enzyme solution in a 100×20 mm petri plate. A total of 1 g of leaves was placed in each plate.

[0096] 4. The plates were incubated at 25° C. in the dark for 16 hr.

[0097] 5. The digested leaf material was pipetted and sieved through a 100 μm nylon screen cloth (Small Parts, Inc., Miami Lakes, Fla.). The filtrate was then transferred to a centrifuge tube, and centrifuged at 1000 rpm for 10 min. All centrifugations for this protocol were done at these conditions.

[0098] 6. The protoplasts collected in a band at the top. The band of protoplasts was then transferred to a clean centrifuge to which 10 ml of a washing solution (0.4 M sucrose and 80 mM KCl) was added. The protoplasts were gently resuspended, then centrifuged.

[0099] 7. Repeated step 6 twice.

[0100] 8. After the last wash, the protoplast density was determined by dispensing a small aliquot onto a hemocytometer. Resuspend the protoplasts to a density of 1×10⁶ protoplasts/ml in eletroporation buffer (80 mM KCl, 4 mM CaCl₂, 2 mM potassium phosphate, pH 7.2, 8% mannitol, autoclave. The protoplasts were allowed to incubate at 8° C. for 2 hr.

[0101] 9. After 2 hr, 0.3 ml (3×10⁵ protoplasts) were transferred to each 0.4 cm cuvette, then placed on ice. GFP-2 (0.6-4 μg/mL) was added to each cuvette except for an unelectroporated control. The protoplasts were electroporated (250V, capacitance 250 μF, and time constant 10-14 ms).

[0102] 10. The protoplasts were allowed to recover for 10 min on ice, then transferred to petri plates (100×20 mm). After 35 min, 10 ml of POM, see above, was added to each plate. The plates were transferred to the dark at 25° C. for 24 hr, then transferred to the light.

[0103] 11. The protoplast cultures were then maintained according to Gallois supra.

[0104] Fluorescence Microscopy

[0105] 1. Under UV light, we observed 8 GFP converted protoplasts out of 3×10⁵ protoplasts.

1 19 1 2063 DNA Solanum tuberosum CDS (3)...(1907) 1 agtaccattc cagttatgac ccggaaaact ccgcctccca ttacacattc ctcccggatc 60 aacccgattc cggccaccgg aagtccctta aaatcatctc cggcattttc ctctcctctt 120 tccttttgct ttctgtagcc ttctttccga tcctcaacaa ccagtcaccg gacttgcaga 180 gtaactcccg ttcgccgccg ccgtcaagag gtgtttctca gggagtctcc gataagactt 240 ttcgagatgt cgtcaatgct agtcacattt cttatgcgtg gtccaatgct atgcttagct 300 ggcaaagaac tgcttaccat tttcaacctc aaaaaaattg gatgaacgat cctaatggtc 360 cattgtacca caagggatgg tatcatcttt tttatcaata caatccagat tcagctattt 420 ggggaaatat cacatggggc catgccgtat ccaaggactt gatccactgg ctctacttgc 480 cttttgccat ggttcctgat caatggtacg atattaacgg tgtctggact gggtccgcct 540 ccatcctacc cgatggtcag atcatgatgc tttataccgg tgtctctgat gattatgtac 600 aagtgcaaaa tcttgcgtac cccaccaact tatctgatcc tctccttcta gactgggtca 660 agtacaaagg caacccggtt ctggttcctc cacccggcat tggtatcaag gactttagag 720 acccgaccac tgcttggacc ggaccccaaa atgggcaatg gcttttaaca atcgggtcta 780 agattggtaa aacgggtatt gcacttgttt atgaaacttc caacttcaca agctttaagc 840 tattggatga agtgctgcat gcggttccgg gtacgggtat gtgggagtgt gtggactttt 900 acccggtatc gactgaaaaa acaaacgggt tggacacatc atataacggc ccgggtgtaa 960 agcatgtgtt aaaagcaagt ttagatgaca ataagcaaga tcactatgct attgggacgt 1020 atgacttgac aaagaacaaa tggacacccg ataacccgga attggattgt ggaattgggt 1080 tgaagctgga ttatgggaaa tattatgcat caaagacatt ttatgacccg aagaaacaac 1140 gaagagtact gtggggatgg attggggaaa ctgatagtga atctgctgac ctgcagaagg 1200 gatgggcatc tgtacagagt attccaagga cagtgcttta cgacaagaag acagggacac 1260 atctacttca gtggccagtt gaagaaattg aaagcttaag agtgggtgat cctattgtta 1320 agcaagtcaa tcttcaacca ggttcaattg agctactcca tgttgactca gctgcagagt 1380 tggatataga agcctcattt gaagtggaca aagtcgcgct ccagggaata attgaagcag 1440 atcatgtagg tttcagctgc tctactagtg gaggtgctgc tagcagaggc attttgggac 1500 catttggtgt cgttgtaatt gctgatcaaa agctatctga gctaacgcca gtttacttct 1560 acatttctaa aggagctgat ggtcgagctg agactcactt ctgtgctgat caaactagat 1620 cctcagaggc tccgggagtt gctaaacaag tttatggtag ttcagtaccc gtgttagacg 1680 gtgaaaaaca ttcgatgaga ttattggagg accactcaat tgtggagagc tttgcccaag 1740 gaggaagaac agtcataaca tcgcgaattt acccaacaaa ggcagtgaat ggagcagcac 1800 gactcttcgt tttcaacaat gccacagggg ctagcgtgac tgcttccgtc aagatttggt 1860 cacttgagtc ggctaatatt cgatccttcc ccttgcaaga cttgtaattc atcaagccat 1920 atcttcttca ttcttttttt catttgaagg ttatttcacc gatgtcccat caagaaaggg 1980 aagagaggga gaatatgtag tgttatactc tacttattcg ccattttagt gatttttcta 2040 ctggactttt gctattcgca aaa 2063 2 1958 DNA Solanum tuberosum CDS (22)...(1815) 2 tcttttgcgt tttgagcaat aatggcaagc ttgtgcaata gtagtagtac atctctcaaa 60 actcctttta cttcttcctc cacttcttta tcttccactc ctaagccctc tcaacttttc 120 atccatggaa aacgtaacca aatgttcaaa gtttcatgca aggttaccaa taataacggt 180 gaccaaaacc aaaacgttga aacaaattct gttgatcgaa gaaatgttct tcttggctta 240 ggtggtcttt atggtgttgc taatgctata ccattagctg catccgctgc tccagctcca 300 cctcctgatc tctcgtcttg tagtatagcc aggattaacg aaaatcaggt ggtgccgtac 360 agttgttgcg cgcctaagcc tgatgatatg gagaaagttc cgtattacaa gttcccttct 420 atgactaagc tccgtgttcg tcagcctgct catgaagcta atgaggagta tattgccaag 480 tacaatctgg cgattagtcg aatgaaagat cttgataaga cacaaccttt aaaccctatt 540 ggttttaagc aacaagctaa tatacattgt gcttattgta acggtgctta tagaattggt 600 ggcaaagagt tacaagttca taattcttgg cttttcttcc cgttccatag atggtacttg 660 tacttccacg agagaatcgt gggaaaattc attgatgatc caactttcgc tttaccatat 720 tggaattggg accatccaaa aggtatgcgt tttcctgcca tgtatgatcg tgaagggact 780 tcccttttcg atgtaacacg tgaccaaagt caccgaaatg gagcagtaat cgatcttggt 840 tttttcggca atgaagttga aacaactcaa ctccagttga tgagcaataa tttaacacta 900 atgtaccgtc aaatggtaac taatgctcca tgtcctcgga tgttctttgg cgggccttat 960 gatctcgggg ttaacactga actcccggga actatagaaa acatccctca cggtcctgtc 1020 cacatctggt ctggtacagt gagaggttca actttgccca atggtgcaat atcaaacggt 1080 gagaatatgg gtcattttta ctcagctggt ttggacccgg ttttcttttg ccatcacagc 1140 aatgtggatc ggatgtggag cgaatggaaa gcgacaggag ggaaaagaac ggatatcaca 1200 cataaagatt ggttgaactc cgagttcttt ttctatgatg aaaatgaaaa cccttaccgt 1260 gtgaaagtca gagactgttt ggacacgaag aagatgggat acgattacaa accaattgcc 1320 acaccatggc gtaacttcaa gcccttaaca aaggcttcag ctggaaaagt gaatacagct 1380 tcacttccgc cagctagcaa tgtattccca ttggctaaac tcgacaaagc aatttcgttt 1440 tccatcaata ggccgacttc gtcaaggact caacaagaga aaaatgcaca agaggagatg 1500 ttgacattca gtagcataag atatgataac agagggtaca taaggttcga tgtgttttcg 1560 aacgtggaca ataatgtgaa tgcgaatgag cttgacaagg cggagtttgc ggggagttat 1620 acaagtttgc cacatgttca tagagctggt gagactaatc atatcgcgac tgttgatttc 1680 cagctggcga taacggaact gttggaggat attggtttgg aagatgaaga tactattgcg 1740 gtgactctgg tgccaaagag aggtggtgaa ggtatctcca ttgaaggtgc gacgatcagt 1800 cttgcagatt gttaattagt ctctattgaa tctgctgaga ttacactttg atggatgatg 1860 ctctgttttt gttttcttgt tctgtttttt cctctgttga aatcagcttt gttgcttgat 1920 ttcattgaag ttgttattca agaataaatc agttacaa 1958 3 1460 DNA Nicotiana tabacum CDS (84)...(1178) 3 tctgtttctt caactcacct taatttgccc aattgagtca ttgtaaaatc tgaaacagaa 60 ccaagagaga agagaaaaaa aatatgggtt caacaagcca gagccagagt aagagtctaa 120 ctcacacaga agacgaagcg ttcttatttg ccatgcaatt ggctagtgct tctgtacttc 180 ctatggtcct aaaatcagcg ttagaacttg accttcttga actcatggct aaagctggtc 240 caggtgcagc catttctcct tctgaattag ctgctcagct ctcaacccag aacccagaag 300 cacccgttat tcttgatcgg atgcttaggc tacttgctac ttactctgtt ctcaattgta 360 ctcttagaac actgtctgat ggcagtgttg agaggcttta tagtctggct ccggtttgta 420 agttcttgac taagaatgct gatggtgttt ctgttgcccc acttttgctt atgaatcaag 480 ataaagttct tatggagagc tggtaccact taaaagatgc agtactagat ggtggaatcc 540 cattcaacaa ggcctatgga atgacagcat ttgagtacca tggcacagat ccaagattca 600 acaaagtttt caaccgtgga atgtctgatc actccactat gtcaatgaaa aagattcttg 660 aggactacaa aggatttgaa ggcctaaatt ccattgttga tgttggtggt ggaactggcg 720 ctactgttaa catgattgtc tccaaacatc cctctattaa gggtattaac tttgatttac 780 cacatgttat tggagatgct ccagcttacc ctggtgtcga gcacgttggt ggcgacatgt 840 ttgccagtgt gccaaaagca gatgccattt tcatgaagtg gatttgtcat gattggagcg 900 acgagcattg cctaaaattc ttgaagaatt gctatgaagc actacctgca aatgggaagg 960 tgataatagc ggagtgcata cttccagagg ccccagatac atcacttgca actaagaata 1020 cagtacatgt tgatattgtg atgttagcac ataacccagg aggcaaagaa aggactgaga 1080 aggaatttga ggctttggct aagggcgctg gttttactgg attcgcaagg cttgttgcgc 1140 ttacaacact tgggtcatgg aattcaacaa ataattaatc gattcctttg gaggattaag 1200 caatatactg ttcattttgc attttgaaat tctacttttc acagagtggc tttactgcga 1260 aataaaagaa atatatagct tttaccttga aaagatcaat gttcaaaggg aaaaaaaaaa 1320 aggaagatga aataattgct ctcagaaaag cagtgtgtta ggaaaaagct ttttagctgg 1380 attttgaatt ttattgtatg tatttctgta atacacatgt attgaaggaa tactagtttt 1440 cgaccaatca tatttctttg 1460 4 1418 DNA Nicotiana tabacum CDS (59)...(1153) 4 attccttcaa cttacccaat taagtcatcg aaaaatctga aacagaacta aaagtaaaat 60 gggttcaaca agcgagagcc agagtaacag tctcactcac acagaagacg aagctttctt 120 atttgccatg caattgtgta gtgcttctgt acttcctatg gtcctaaaat cagccgtaga 180 acttgacctt cttgagctaa tggctaaggc tggtccaggt gcagctattt ctccttctga 240 attagctgct cagctctcaa ctcagaaccc agaagcacct gttatgcttg atcggatgct 300 taggctactt gcttcttact ctgttctcaa ttgtactctt agaacactgc ctgatagcag 360 tgttgagagg ctttatagtc tggctcccgt ctgtaagtac ttgactaaga atgctgatgg 420 tgtttctgtt gccccacttt tgcttatgaa tcaagataaa gttcttatgg agagctggta 480 ccacttaaaa gatgcagtac tagatggcgg aatcccattc aacaaagcct atggaatgac 540 agcatttgag taccatggca cagatccaag attcaacaaa gtgttcaacc gtggaatgtc 600 tgatcactcc actatgtcaa tgaagaagat tcttgaggac tacaaaggat ttgaaggcct 660 aaattccatt gttgatgttg gtggtggaac gggtgctact gttaacatga ttgtctctaa 720 atatccctct attaagggca ttaactttga tttgccacat gtaattggag atgctccaac 780 ttaccccggt gtcgagcacg ttggtggcga catgtttgct agtgtgccaa aagcagatgc 840 cattttcatg aagtggattt gtcatgattg gagcgatgag cattgcctaa aattcttgaa 900 gaattgctat gaagcactac ctgcaaatgg gaaggtgata attgcagagt gcatacttcc 960 agaggcccca gatacatcac ttgcaactaa gaatacagta catgttgata ttgttatgtt 1020 agcacataac ccaggaggca aagaaaggac tgagaaggaa tttgaggctt tggctaaggg 1080 cgctggtttt actggattcg caaggcttgt tgcgcttaca acacttgggt catggaattc 1140 aacaagtaat taatcgattc cttaatttga aggattaagc aatatactgt tcgttttgca 1200 tttggaaatt ctacttttct cagagtggct tgactgtgaa ataaaagaaa tatagctttt 1260 aacttgaaaa gattgatgtt caaaagaaaa aaaggaagat gaaataattg ctctcagaaa 1320 agcaatgtgt taggaaaaag cttttttagc tggattttga attttactgt atgtatttct 1380 gttatacaca tgtattgaag gaatactagt tttcgacc 1418 5 1419 DNA Nicotiana tabacum CDS (92)...(1165) 5 atttctttct ctttcccttg aactgtgttt tcattttttc tgctctgaaa caatagtgtt 60 ttccttgtag attttaagtt aaaagaaaac catgggtagc ttggatgttg aaaaatcagc 120 tattggttgg gctgctagag acccttctgg tctactttca ccttatacct atactctcag 180 aaacacagga cctgaagatg tgcaagtcaa agttttgtat tgtggacttt gccacagtga 240 tcttcaccaa gttaaaaatg atcttggcat gtccaactac cctctggttc ctggacatga 300 agtggtggga aaagtagtgg aggtaggagc agatgtgtca aaattcaaag tgggggacac 360 agttggagtt ggattactcg ttggaagttg taggaactgt ggcccttgca agagagaaat 420 agagcaatat tgcaacaaga agatttggaa ttgcaatgat gtctacactg atggcaaacc 480 cacccaaggt ggttttgcta attctatggt tgttgatcaa aactttgtgg tgaaaattcc 540 agagggtatg gcaccagaac aagcagcacc tctattatgt gctggcataa cagtatacag 600 tccattcaac cattttggtt ttaatcagag tggatttaga ggaggaattt tgggattagg 660 aggagttgga catatgggag tgaaaatagc aaaggcaatg ggacatcatg ttactgtcat 720 tagttcttca aataagaaga gacaagaggc attggaacat cttggtgcag atgattatct 780 tgttagttca gacactgata aaatgcaaga agctgctgat tcacttgact atattattga 840 tactgtccct gttggccatc ctcttgaact ttatctttct ttgcttaaaa ttgatggcaa 900 acttatcttg atcggagtta tcaacacccc cttgcaattt atctctccca tggttatgct 960 cgggagaaag agcatcactg gaagctttat tggtagcatg aaggaaacag aggaaatgct 1020 agacttctgc aaagagaaag gtgtgacttc acagattgag atagtgaaaa tggattatat 1080 caacactgca atggagaggt tggagaaaaa tgatgtgagc tacagatttg ttgttgatgt 1140 tgctggaagc aagcttgacc agtaattgca caagaaaaac aacatggaat ggttcactat 1200 tatacaacaa ggctatgaga aaaatagtac tcctcaactt tgatgtcatc tttgttacct 1260 ttgttttatt ttccacctgt attatcatat ttggtggtcg agagtgacgt ttatgtatat 1320 tttctttctt caaaacaatc ttaaatgaat ttggatgttg gtgacgattt tgaaatatac 1380 caaccatgca aacttacttt ggtagaaaaa aaaaaaaaa 1419 6 1398 DNA Nicotiana tabacum CDS (88)...(1161) 6 attcctcttt cccttgaact gtgttttcgt tttttctgct ctaaaacaat cgtgtgttcc 60 ttctagattt taagtttaaa gaacatcatg ggtggcttgg aagttgagaa aacaactatt 120 ggttgggctg ctagagaccc ttctggtgta ctttcacctt atacctatac tctcagaaac 180 acaggacctg aagatgtgga agtcaaagtt ttgtattgtg ggctctgtca cactgatctt 240 caccaagtta aaaatgatct tggcatgtcc aactaccctc tggttcctgg acatgaagtg 300 gtgggagaag tggtggaggt aggaccagat gtgtcaaaat tcaaagttgg ggacacagtt 360 ggagttggat tactcgttgg aagttgcagg aactgtggcc cttgcaagag agatatagag 420 caatattgca acaagaagat ttggaactgc aatgatgtct acactgatgg caaacccacc 480 caaggtggtt ttgctaaatc catggttgtt gatcaaaagt ttgtggtgaa aattccagag 540 ggtatggcac cagaacaagc agcacctcta ttatgtgctg gtataacagt atacagtcca 600 ttgaaccatt ttggtttcaa acagagtgga ttaagaggag gaattttggg attaggagga 660 gtgggacaca tgggagtgaa aatagcaaag gcaatgggac atcatgttac tgtcattagt 720 tcttcaaata agaagagaca agaggcattg gaacatcttg gtgcagatga ttatcttgtc 780 agttcagaca ctgataaaat gcaagaggct tctgattcac ttgactatat tattgatact 840 gtccctgttg gccatcctct tgaaccttat ctttctttgc ttaaaattga tggcaaactt 900 atcttgatgg gagttatcaa cacccccttg caatttatct cccccatggt tatgctcggg 960 agaaagagca tcacaggaag ctttattggt agcatgaagg aaacagagga aatgctagat 1020 ttctgcaaag agaaaggtgt gacttcacag attgagatag tgaaaatgga ttatatcaac 1080 actgcaatgg agaggttgga gaaaaatgat gtgaggtaca gatttgtggt tgatgttatt 1140 ggaagcaagc ttgaccagta attatattac acaagaaaaa caacatggaa tggttcacta 1200 ttatacaagg ctgtgagaat actaaacttt gatgtcgtct tttgtatcct tttgttttat 1260 ttgccacctg tattttctta tttggtgatc gagagtgacg tttatgtatt attttctttc 1320 ttcaaaacaa tttaatgtat gaatttggat gttggtgaaa aaaaaaaaaa aaaaaaaaaa 1380 aaaaaaaaaa aaaaaaaa 1398 7 1533 DNA Carthamus tinctorius CDS (106)...(1296) 7 gctcacttgt gtggtggagg agaaaaacag aactcacaaa aagctttgcg actgccaaga 60 acaacaacaa caacaagatc aagaagaaga agaagaagat caaaaatggc tcttcgaatc 120 actccagtga ccttgcaatc ggagagatat cgttcgtttt cgtttcctaa gaaggctaat 180 ctcagatctc ccaaattcgc catggcctcc accctcggat catccacacc gaaggttgac 240 aatgccaaga agccttttca acctccacga gaggttcatg ttcaggtgac gcactccatg 300 ccaccacaga agatagagat tttcaaatcc atcgagggtt gggctgagca gaacatattg 360 gttcacctaa agccagtgga gaaatgttgg caagcacagg atttcttgcc ggaccctgca 420 tctgaaggat ttgatgaaca agtcaaggaa ctaagggcaa gagcaaagga gattcctgat 480 gattactttg ttgttttggt tggagatatg attacagagg aagccctacc tacttaccaa 540 acaatgctta ataccctaga tggtgtacgt gatgagactg gggctagcct tacgccttgg 600 gctgtctgga ctagggcttg gacagctgaa gagaacaggc atggcgatct tctccacacc 660 tatctctacc tttctgggcg ggtagacatg aggcagatac agaagacaat tcagtatctc 720 attgggtcag gaatggatcc tcgtaccgaa aacagcccct accttgggtt catctacaca 780 tcgtttcaag agcgtgccac atttgtttct cacggaaaca ccgccaggca tgcaaaggat 840 catggggacg tgaaactggc gcaaatttgt ggtacaatcg cgtctgacga aaagcgtcac 900 gagaccgctt atacaaagat agtcgaaaag ctattcgaga tcgatcctga tggcaccgtt 960 cttgcttttg ccgacatgat gaggaaaaag atctcgatgc ccgcacactt gatgtacgat 1020 gggcgtgatg acaacctctt cgaacatttc tcggcggttg cccaaagact cggcgtctac 1080 accgccaaag actacgccga catactggaa tttctggtcg ggcggtggaa agtggcggat 1140 ttgaccggcc tatctggtga agggcgtaaa gcgcaagatt atgtttgcgg gttgccacca 1200 agaatcagaa ggctggagga gagagctcaa gggcgagcaa aggaaggacc tgttgttcca 1260 ttcagctgga ttttcgatag acaggtgaag ctgtgaagaa aaaaaaaacg agcagtgagt 1320 tcggtttctg ttggcttatt gggtagaggt taaaacctat tttagatgtc tgtttcgtgt 1380 aatgtggttt tttttcttct aatcttgaat ctggtattgt gtcgttgagt tcgcgtgtgt 1440 gtaaacttgt gtggctgtgg acatattata gaactcgtta tgccaatttt gatgacggtg 1500 gttatcgtct cccctggtgt ttttttattg ttt 1533 8 1643 DNA Ricinus communis CDS (1)...(1239) 8 ttccggcaaa taacaaaaaa ccaaaagaaa aaggtaagaa aaaaaacaat ggctctcaag 60 ctcaatcctt tcctttctca aacccaaaag ttaccttctt tcgctcttcc accaatggcc 120 agtaccagat ctcctaagtt ctacatggcc tctaccctca agtctggttc taaggaagtt 180 gagaatctca agaagccttt catgcctcct cgggaggtac atgttcaggt tacccattct 240 atgccacccc aaaagattga gatctttaaa tccctagaca attgggctga ggagaacatt 300 ctggttcatc tgaagccagt tgagaaatgt tggcaaccgc aggatttttt gccagatccc 360 gcctctgatg gatttgatga gcaagtcagg gaactcaggg agagagcaaa ggagattcct 420 gatgattatt ttgttgtttt ggttggagac atgataacgg aagaagccct tcccacttat 480 caaacaatgc tgaatacctt ggatggagtt cgggatgaaa caggtgcaag tcctacttct 540 tgggcaattt ggacaagggc atggactgcg gaagagaata gacatggtga cctcctcaat 600 aagtatctct acctatctgg acgagtggac atgaggcaaa ttgagaagac aattcaatat 660 ttgattggtt caggaatgga tccacggaca gaaaacagtc cataccttgg gttcatctat 720 acatcattcc aggaaagggc aaccttcatt tctcatggga acactgcccg acaagccaaa 780 gagcatggag acataaagtt ggctcaaata tgtggtacaa ttgctgcaga tgagaagcgc 840 catgagacag cctacacaaa gatagtggaa aaactctttg agattgatcc tgatggaact 900 gttttggctt ttgctgatat gatgagaaag aaaatttcta tgcctgcaca cttgatgtat 960 gatggccgag atgataatct ttttgaccac ttttcagctg ttgcgcagcg tcttggagtc 1020 tacacagcaa aggattatgc agatatattg gagttcttgg tgggcagatg gaaggtggat 1080 aaactaacgg gcctttcagc tgagggacaa aaggctcagg actatgtttg tcggttacct 1140 ccaagaatta gaaggctgga agagagagct caaggaaggg caaaggaagc acccaccatg 1200 cctttcagct ggattttcga taggcaagtg aagctgtagg tggctaaagt gcaggacgaa 1260 accgaaatgg ttagtttcac tctttttcat gcccatccct gcagaatcag aagtagaggt 1320 agaattttgt agttgctttt ttattacaag tccagtttag tttaaggtct gtggaaggga 1380 gttagttgag gagtgaattt agtaagttgt tgatactgtt gtgttcttgt gttgtcatga 1440 gtctgcttga tagtgagttt cttttgtttc cttttgttgt gttcttttat ctggtctctc 1500 tctctctctc tctctctttt tctcttatcc caagtgtctc aagtataata agcaaacgat 1560 ccatgtggca attttgatga tggtgatcag tctcacaact tgatcttttg tcttctattg 1620 gaaacacagc ctgcttgttt gaa 1643 9 2569 DNA Arabidopsis thaliana exon (236)...(729) Exon 1 9 cacaccatca ctaataaatt tccttctcct ttcaagttgt agctaactta tataagacat 60 aagcgtgcga accagagaca gagatagaaa ttgagagacg ataagcaaag tagaaaacac 120 aagtttctct cacacacatt atctctttct ctattaccac cactcattca taacagaaac 180 ccaccaaaaa ataaaaagag agacttttca ctctggggag agagctcaag ttctaatggc 240 gaacttggtc ttatcagaat gtggtatacg acctctcccc agaatctaca caacacccag 300 atccaatttc ctctccaaca acaacaaatt cagaccatca ctttcttctt cttcttacaa 360 aacatcatca tctcctctgt cttttggtct gaattcacga gatgggttca cgaggaattg 420 ggcgttgaat gtgagcacac cattaacgac accaatattt gaggagtctc cattggagga 480 agataataaa cagagattcg atccaggtgc gcctcctccg ttcaatttag ctgatattag 540 agcagctata cctaagcatt gttgggttaa gaatccatgg aagtctttga gttatgtcgt 600 cagagacgtc gctatcgtct ttgcattggc tgctggagct gcttacctca acaattggat 660 tgtttggcct ctctattggc tcgctcaagg aaccatgttt tgggctctct ttgttcttgg 720 tcatgactgg taaacttaaa aaccctaact tttttcttgt tttctcctct gctttagtct 780 cctttagcct ttgatttggt caactttgga tgattccaaa gaaccaatcg aacaaattgg 840 tctttatcca tatctcttca aatagcttta ggacataatt ggtctctcag gtaacaagct 900 gtcattatca tcatactcat catgttgcta gtagaccaac ccaattggca actgtttgtt 960 ggttttgcaa ctgtgtaatc tgctttgaat tgtgaacaaa attattgatt tatgttgatt 1020 acattgcagt ggacatggta gtttctcaaa tgatccgaag ttgaacagtg tggtcggtca 1080 tcttcttcat tcctcaattc tggtcccata ccatggctgg tgagttttgc tttcagacca 1140 ttcttctcta aaaccacttg cagaatctca tcttcttcat gtaaaaatat gactttgcag 1200 gagaattagt cacagaactc accaccagaa ccatggacat gttgagaatg acgaatcttg 1260 gcatcctgta agtcaaaaac gtattttttt ggttatcttg ttttagtcct gtggtgtttc 1320 ttagatgcag ttttattaac tgtttctgta actgcagatg tctgagaaaa tctacaatac 1380 tttggacaag ccgactagat tctttagatt tacactgcct ctcgtgatgc ttgcataccc 1440 tttctacttg gtaagaactc ctctatttgt tatggtaact taagctgcca caccaagtaa 1500 aaaagctcat gtctattctt ctgtttcagt gggctcgaag tccggggaaa aagggttctc 1560 attaccatcc agacagtgac ttgttcctcc ctaaagagag aaaggatgtc ctcacttcta 1620 ctgcttgttg gactgcaatg gctgctctgc ttgtttgtct caacttcaca atcggtccaa 1680 ttcaaatgct caaactttat ggaattcctt actgggtaat gcgccgctgt tactcccctg 1740 tttcagcctg agcaatttgt gtattatttc ctctgcctta ctcaaaaagg tttttatgtc 1800 aaatacagat aaatgtaatg tggttggact ttgtgactta cctgcatcac catggtcatg 1860 aagataagct tccttggtac cgtggcaagg taaaatacat attctctgct tccactgttc 1920 tttgactaca tcgctctttc ttttaaggtt aaagccaact ggtgtgtaaa tctcatgatt 1980 ctcccaaaac aggagtggag ttacctgaga ggaggactta caacattgga tcgtgactac 2040 ggattgatca ataacatcca tcatgatatt ggaactcatg tgatacatca tcttttcccg 2100 cagatcccac attatcatct agtagaagca gtaagtaaat tgaaagtaaa gactgtttgt 2160 gtttttggtg ttcatgctag tttccctgac tcttgctcca ctgttatgca gacagaagca 2220 gctaaaccag tattagggaa gtattacagg gagcctgata agtctggacc gttgccatta 2280 catttactgg aaattctagc gaaaagtata aaagaagatc attacgtgag cgacgaagga 2340 gaagttgtat actataaagc agatccaaat ctctatggag aggtcaaagt aagagcagat 2400 tgaaatgaag caggcttgag attgaagttt tttctatttc agaccagctg attttttgct 2460 tactgtatca atttattgtg tcacccacca gagagttagt atctctgaat acgatcgatc 2520 agatggaaac aacaaatttg tttgcgatac tgaagctata tataccata 2569 10 3879 DNA Arabidopsis thaliana exon (780)...(1685) Exon 1 10 aaagatagta tttgttgata aatatgggga tatttatcct atattatctg tatttttctt 60 accattttta ctctattcct ttatctacat tacgtcatta cactatcata agatatttga 120 atgaacaaat tcatgcaccc accagctata ttaccctttt ttattaaaaa aaaacatctg 180 ataataataa caaaaaaatt agagaaatga cgtcgaaaaa aaaagtaaga acgaagaaga 240 agtgttaaac ccaaccaatt ttgacttgaa aaaaagcttc aacgctcccc ttttctcctt 300 ctccgtcgct ctccgccgcg tcccaaatcc ccaattcctc ctcttctccg atcaattctt 360 cccaagtaag cttcttcttc ctcgattctc tcctcagatt gtttcgtgac ttctttatat 420 atattcttca cttccacagt tttcttctgt tgttgtcgtc gatctcaaat catagagatt 480 gattaaccta attggtcttt atctagtgta atgcatcgtt attaggaact ttaaattaag 540 atttaatcgt taatttcatg attcggattc gaattttact gttctcgaga ctgaaatatg 600 caacctattt tttcgtaatc gttgtgatcg aattcgattc ttcagaattt atagcaattt 660 tgatgctcat gatctgtcta cgctacgttc tcgtcgtaaa tcgaagttga taatgctatg 720 tgtttgttac acaggtgtgt gtatgtgtga gagaggaact atagtgtaaa aaattcataa 780 tggaagtctg caattgtatt gaaccgcaat ggccagcgga tgaattgtta atgaaatacc 840 aatacatctc cgatttcttc attgcgattg cgtatttttc gattcctctt gagttgattt 900 actttgtgaa gaaatcagcc gtgtttccgt atagatgggt acttgttcag tttggtgctt 960 ttatcgttct ttgtggagca actcatctta ttaacttatg gactttcact acgcattcga 1020 gaaccgtggc gcttgtgatg actaccgcga aggtgttaac cgctgttgtc tcgtgtgcta 1080 ctgcgttgat gcttgttcat attattcctg atcttttgag tgttaagact cgggagcttt 1140 tcttgaaaaa taaagctgct gagctcgata gagaaatggg attgattcga actcaggaag 1200 aaaccggaag gcatgtgaga atgttgactc atgagattag aagcacttta gatagacata 1260 ctattttaaa gactacactt gttgagcttg gtaggacatt agctttggag gagtgtgcat 1320 tgtggatgcc tactagaact gggttagagc tacagctttc ttatacactt cgtcatcaac 1380 atcccgtgga gtatacggtt cctattcaat taccggtgat taaccaagtg tttggtacta 1440 gtagggctgt aaaaatatct cctaattctc ctgtggctag gttgagacct gtttctggga 1500 aatatatgct aggggaggtg gtcgctgtga gggttccgct tctccacctt tctaattttc 1560 agattaatga ctggcctgag ctttcaacaa agagatatgc tttgatggtt ttgatgcttc 1620 cttcagatag tgcaaggcaa tggcatgtcc atgagttgga actcgttgaa gtcgtcgctg 1680 atcaggtttt acattgctga gaatttctct tctttgctat gttcatgatc ttgtctataa 1740 cttttcttct cttattatag gtggctgtag ctctctcaca tgctgcgatc ctagaagagt 1800 cgatgcgagc tagggacctt ctcatggagc agaatgttgc tcttgatcta gctagacgag 1860 aagcagaaac agcaatccgt gcccgcaatg atttcctagc ggttatgaac catgaaatgc 1920 gaacaccgat gcatgcgatt attgcactct cttccttact ccaagaaacg gaactaaccc 1980 ctgaacaaag actgatggtg gaaacaatac ttaaaagtag taaccttttg gcaactttga 2040 tgaatgatgt cttagatctt tcaaggttag aagatggaag tcttcaactt gaacttggga 2100 cattcaatct tcatacatta tttagagagg taacttttga acagctctat gtttcataag 2160 tttatactat ttgtgtactt gattgtcata ttgaatcttg ttgcaggtcc tcaatctgat 2220 aaagcctata gcggttgtta agaaattacc catcacacta aatcttgcac cagatttgcc 2280 agaatttgtt gttggggatg agaaacggct aatgcagata atattaaata tagttggtaa 2340 tgctgtgaaa ttctccaaac aaggtagtat ctccgtaacc gctcttgtca ccaagtcaga 2400 cacacgagct gctgactttt ttgtcgtgcc aactgggagt catttctact tgagagtgaa 2460 ggttattatc ttgtatcttg ggatcttata ccatagctga aagtatttct taggtcttaa 2520 ttttgatgat tattcaaata taggtaaaag actctggagc aggaataaat cctcaagaca 2580 ttccaaagat tttcactaaa tttgctcaaa cacaatcttt agcgacgaga agctcgggtg 2640 gtagtgggct tggcctcgcc atctccaaga ggtttgagcc ttattaaaag acgttttttt 2700 ccaacttttt cttgtcttct gtgttgttaa aagtttactc ataagcgttt aatatgacaa 2760 ggtttgtgaa tctgatggag ggtaacattt ggattgagag cgatggtctt ggaaaaggat 2820 gcacggctat ctttgatgtt aaacttggga tctcagaacg ttcaaacgaa tctaaacagt 2880 cgggcatacc gaaagttcca gccattcccc gacattcaaa tttcactgga cttaaggttc 2940 ttgtcatgga tgagaacggg ttagtataag cttctcacct ttctctttgc aaaatctctc 3000 gccttacttc ttgcaaatgc agatattggc gtttagaaaa aacgcaaatt taatcttatg 3060 agaaaccgat gattattttg gttgcagggt aagtagaatg gtgacgaagg gacttcttgt 3120 acaccttggg tgcgaagtga ccacggtgag ttcaaacgag gagtgtctcc gagttgtgtc 3180 ccatgagcac aaagtggtct tcatggacgt gtgcatgccc ggggtcgaaa actaccaaat 3240 cgctctccgt attcacgaga aattcacaaa acaacgccac caacggccac tacttgtggc 3300 actcagtggt aacactgaca aatccacaaa agagaaatgc atgagctttg gtctagacgg 3360 tgtgttgctc aaacccgtat cactagacaa cataagagat gttctgtctg atcttctcga 3420 gccccgggta ctgtacgagg gcatgtaaag gcgatggatg ccccatgccc cagaggagta 3480 attccgctcc cgccttcttc tcccgtaaaa catcggaagc tgatgttctc tggtttaatt 3540 gtgtacatat cagagattgt cggagcgttt tggatgatat cttaaaacag aaagggaata 3600 acaaaataga aactctaaac cggtatgtgt ccgtggcgat ttcggttata gaggaacaag 3660 atggtggtgg tataatcata ccatttcaga ttacatgttt gactaatgtt gtatccttat 3720 atatgtagtt acattcttat aagaatttgg atcgagttat ggatgcttgt tgcgtgcatg 3780 tatgacattg atgcagtatt atggcgtcag ctttgcgccg cttagtagaa caacaacaat 3840 ggcgttactt agtttctcaa tcaacccgat ctccaaaac 3879 11 1200 DNA Arabidopsis thaliana CDS (53)...(1024) 11 cgttgctgtc gaagttaggc caagaaaccc atttaaaaaa aaagagagag agatggagag 60 tttcccgatc atcaatctcg agaagcttaa tggagaagag agagcaatca ctatggagaa 120 gatcaaagac gcttgtgaaa actggggctt ctttgagtgt gtgaaccatg ggatttcact 180 cgagcttttg gacaaagtgg agaagatgac caaggaacat tacaagaagt gcatggaaga 240 gagattcaag gaatcgatta agaacagagg tcttgactct cttcgctctg aagtcaacga 300 cgttgactgg gaatccactt tctacctcaa gcaccttccc gtctctaata tctccgatgt 360 ccctgatctc gacgacgatt acagaacgtt aatgaaagac ttcgccggaa agatagagaa 420 gttgtcggag gagctactgg atctgctgtg cgagaatctc ggtttagaga agggttattt 480 aaaaaaggtg ttttacgggt cgaaaagacc gacttttgga accaaagtca gcaattatcc 540 accttgtcct aatccggacc tagtcaaggg tctccgagcc cacaccgacg ccggcggcat 600 catcctcctc ttccaagacg acaaagtcag tggacttcag cttcttaaag acggcgagtg 660 ggtcgatgtt cctccggtta agcattcaat cgtcgttaat ctcggcgatc aacttgaggt 720 gataaccaat gggaagtaca agagtgtgga acatagagtg ctatctcaga cagacggaga 780 aggaagaatg tcgatcgcat cattctataa tccgggaagc gactctgtta tttttccggt 840 gccggagctg atcggaaaag aagcagagaa ggagaagaaa gagaactatc cgagatttgt 900 gtttgaagat tacatgaaac tctactctgc tgtcaagttt caggccaagg aaccaaggtt 960 tgaagccatg aaagctatgg agacaactgt ggccaacaat gttggaccat tggccactgc 1020 gtgaatgata tgtaactggt taataaatat atatatatat atatatatag tctttatata 1080 atgtcttaga aacttgatta ttcactatac gaataatttt gttcatgttg ttgtatgttt 1140 aagtggtgaa tgtgttatat atgggaatta atgttttctg ttcgaaaaaa aaaaaaaaaa 1200 12 3438 DNA Arabidopsis thaliana exon (1212)...(1358) Exon 1 12 gttacttttc aaatcttccc tcatattata tagccattga tatcatagag gatgtgagtt 60 ttaacttaat atttacccgt ttgaaactag ctatttactt aaatatgaat tataatctag 120 tttaactacc aaaaacatca tatggggaca agaaaaagta ataaaacgta tggaaaattt 180 tgtagatgtt ataaatggat aattattcaa gtgataatct atcactttga tcttatctct 240 ttatccaatt taattacttt gtctctaagt gatttgcttc caaaatctaa gtgtagtcta 300 tcctatttct atcttatcct atcatataat cttctatata tatgtgagtc cgatgttgta 360 aagcgtacga gagagagtaa tgaagagtga agtgttatat tgttctctcg tccacttcca 420 ctctctcttt tatctcttac ttacttcttc gtaagatcat tacatataat aaataatatt 480 atttatgttt gtgttatatt taataacagt aaaaagtttt aaaacgttga aaaaattagc 540 cgacatagaa tacaaaagag ggttagcatc gggggagaaa cgtggaccaa catgatacac 600 cctccaaaat agtccccaag ttgaaacatt gacatgtttc gctttttctt ttctgtgtat 660 actttttttt tctgtgggtc acattattta atatttgtat acaagcagct attttacatg 720 gagatttcct gtcggtatag cgtcctcatt tctccatcgc ttccactttt ttcctatact 780 aatttgatct aattaattca tatgtcaaaa cattaagaaa atgaaactcg taattcatac 840 ttgaatttaa tagattaatt aaaatgctat ttattggcaa aataaactcg gtttatatct 900 aaattttaga atcactaaaa ctttttgccc aaaaaaaaat aaaaataaat cactaaaaca 960 aaaaacaatc aaaagaaaac ccatgttggt aaatcggata atgaaaataa ttagaatccc 1020 cgtcctttgt gtattttggc gtagcatgaa actatataat aaacatgcat tcattcttag 1080 acttctcgta gcttatcaac aacaacgcgc tcgatctctc tcagcctgtc tgacaactct 1140 ttctctagtt ctagagtttt caatttattg ttgagccttt tattaaaaaa aaaaaaacaa 1200 gaacaaaaga aatggttcaa ttgtcaagaa aagctacatg caacagccat ggccaagtct 1260 cttcgtattt ccttggttgg gaagagtacg agaagaatcc ttacgacgtt accaagaacc 1320 ctcaaggcat tatccagatg ggtcttgcgg aaaatcaggt aaacaaatat tattcaacag 1380 catgtgatat atatatactt atgtatatca tgacagagag actaatttaa agtatgttta 1440 attttattgg atttctgtag ctatgctttg atctactaga gtcatggctt gcacaaaaca 1500 cagacgcagc ctgtttcaag agagatggcc agtctgtttt ccgggaactc gctctctttc 1560 aagactacca tggcctctct tccttcaaaa atgtaagatt attaattgta tttatcaaat 1620 ttatttgtag gttgctgatc ttgctcgaat gattttcagg cctttgctga tttcatgtca 1680 gaaaatagag gaaatcgagt ttcttttgat tcaaacaacc ttgtgctcac tgctggagcc 1740 acttccgcaa acgagactct aatgttttgt cttgcagatc ccggtgacgc tttcttgctt 1800 cccacgccat attatccagg gttagtccac tgtttgctta cacgtaaaat ttccatcatt 1860 cctacgaact tgacttaact aaaactcatg tttatttttg tacttcaggt ttgataggga 1920 tctaaaatgg cgaaccgggg ttgagattgt accaatccaa agctcaagta ctaacgggtt 1980 tcgcataacg aaacttgcac tcgaagaagc ctacgagcaa gccaagaagc ttgacctaaa 2040 cgtcaaagga atactcatca ccaacccatc taaccctttg ggtacgacaa caacccaaac 2100 cgaactcaac attctatttg atttcatcac caagaataag aatatacatt tagtaagtga 2160 cgagatatat tcgggcacag tattcaactc ttcagaattc atcagcgtca tggagattct 2220 aaaaaataat caactcgaaa acaccgatgt tttgaaccga gtccacattg tttgtagctt 2280 atctaaagat ctaggcctcc ctggttttag agttggagcc atttactcca atgacaaaga 2340 tgtcatctct gccgctacaa aaatgtcaag tttcggcctt gtctcctccc agacacaata 2400 cctactatcc tcattattat ctgacaagaa gttcactaag aactacctta gagagaacca 2460 aaaacggctc aagaacagac agagaaagct cgtgttgggt ctagaggcca tcgggatcaa 2520 atgtctgaag agtaatgcgg gactcttttg ttgggtcgac atgagacctc tccttagatc 2580 taaaacgttc gaagcggaaa tggatctttg gaagaagatt gtttacgaag tgaagctcaa 2640 catctctcct ggttcgtcgt gccattgtga agaaccgggt tggtttagag tttgtttcgc 2700 gaacatgatt gatgagacat taaagcttgc tttaaagaga ttgaagatgt tggttgatga 2760 tgaaaactca agtagaagat gccaaaagag taaaagcgaa agactaaacg gttcgaggaa 2820 gaagacgatg tcaaatgtct ctaactgggt tttccgacta tcgtttcacg accgtgaggc 2880 tgaggaacga tagtccggtt tttgttttga agttcttttt ttttgtttcc cacacattgc 2940 aagtgattct gtaatttttt ttatcacgag agagagtgta aaaaaatgga aatgcaacgt 3000 gcttactctg atcctagatt ttagaaaacc gttgaagact tcttagagca agtccatcgg 3060 cagtttttaa tgggtttcta atgggtttct agctaattaa aagtccaaaa ttaaatgaaa 3120 acccaactaa ataattagga tccatcccaa tattaggttt tttggatggg tttttagacg 3180 gcgacgtggt cgactgtgag tcgtcggaaa acaaaaaaaa tcacaacact catgttttcc 3240 tttttcctct cgtttttcac ttttttgttt tgtccgacgg ccggcgattc gaatcgattt 3300 gatctccggt gtatcgaaca tgaaatcggg agagaagagc caaatcatcg acgacttggt 3360 tcaccaattc cattcttcga accatactca tataagagtt tcttggcttc tctctaaaac 3420 tcttctaatt ttctgata 3438 13 68 DNA Artificial Sequence Beneficial Oligonucleotide-Contains both DNA and RNA 13 caggtcaagt gcaacgtagg atgattttta ucaaccuacg ttgcacuuga ccuggcgcgt 60 tttcgcgc 68 14 68 DNA Artificial Sequence Beneficial Oligonucleotide-Contains Both DNA and RNA 14 caggtcaagt gctacgtagg atgattttta ucaaccuacg tagcacuuga ccuggcgcgt 60 tttcgcgc 68 15 24 DNA Jelly Fish 15 atggtgagca agggcgagga gctg 24 16 24 DNA Artificial Sequence Mutation 16 atggtgagca agggctagga gctg 24 17 24 DNA Artificial Sequence Mutation 17 atggtgagca agggcaggag ctgt 24 18 68 DNA Artifical Sequence Beneficial Oligonucleotide-Contains Both DNA and RNA 18 gtgagcaagg gcgaggagct gttcattttu gaacagcucc tcgcccuugc ucacgcgcgt 60 tttcgcgc 68 19 68 DNA Artificial Sequence Beneficial Oligonucleotide-Contains Both DNA and RNA 19 tgagcaaggg ctcggagctg ttcacttttg ugaacagcuc cgagcccuug cucagcgcgt 60 tttcgcgc 68 

We claim:
 1. A method of making a localized mutation in a target gene in a plant cell comprising the steps of: a. adhering to a particle a recombinagenic oligonucleobase, which contains a first homologous region which has a sequence identical to the sequence of at least 6 base pairs of a first fragment of the target gene and a second homologous region which has a sequence identical to the sequence of at least 6 base pairs of a second fragment of the target gene, and an intervening region which contains at least 1 nucleobase heterologous to the target gene, which intervening region connects the first homologous region and the second homologous region; b. introducing the particle into a cell of a population of plant cells; c. identifying a cell of the population cell having a mutation located between the first and second fragments of the target gene.
 2. The method of claim 1, wherein the recombinagenic oligonucleobase is a MDON and each of the homologous regions contains an RNA segment of at least 6 RNA-type nucleotides.
 3. The method of claim 2, wherein the intervening region is at least 3 nucleotides in length.
 4. The method of claim 2, which further comprises the step of culturing the identified cell so that a plant is generated.
 5. The method of claim 2, wherein the first RNA segment contains at least 8 contiguous 2′-Substituted Ribonucleotides.
 6. The method of claim 5 wherein the second RNA segment contains at least 8 contiguous 2′-Substituted Ribonucleotides.
 7. The method of claim 2, wherein the sequence of the mutated target gene is homologous with the sequence of the MDON.
 8. The method of claim 2, wherein the adhering step is performed in a solution comprising 1.1-1.4 M NaCl and 18-22 μM spermidine and at least 14 μg/ml MDON.
 9. The method of claim 2, wherein the target gene is a first ALS gene, a second ALS gene, a psbA gene, a threonine dehydratase gene, a dihydrodipicolinate synthase gene, or an S14/rp59 gene
 10. The method of claim 9, wherein the plant cell is a maize, wheat, rice or lettuce cell.
 11. The method of claim 9, wherein the plant cell is a potato, tomato, canola, soybean or cotton cell.
 12. The method of claim 2, wherein the target gene selected from the group consisting of the genes encoding acid invertase, UDP-glucose pyrophosphorylase, polyphenol oxidase, O-methyl transferase, cinnamyl alcohol dehydrogenase, etr-1 or a homolog thereof, ACC synthase and ACC oxidase.
 13. The method of claim 12, where the plant cell is from a maize, wheat, rice or lettuce plant.
 14. The method of claim 12, where the plant cell is from a potato, tomato, canola, soybean or cotton plant.
 15. The method of claim 2, which further comprises making seeds from the plant or from progeny of the plant.
 16. A method of making a localized mutation in a target gene in a plant cell having a cell wall comprising the steps of: a. perforating the cell walls of a population of plant cells; b. introducing a recombinagenic oligonucleobase, which contains a first homologous region which has a sequence identical to the sequence of at least 6 base pairs of a first fragment of the target gene and a second homologous region which has a sequence identical to the sequence of at least 6 base pairs of a second fragment of the target gene, and an intervening region which contains at least 1 nucleobase heterologous to the target gene, which intervening region connects the first homologous region and the second homologous region; c. identifying a cell of the population having a mutation located between the first and second fragments of the target gene.
 17. The method of claim 16, wherein the recombinagenic oligonucleobase is a MDON and each of the homologous regions contains an RNA segment of at least 6 RNA-Type nucleotides.
 18. The method of claim 17, which further comprises the step of culturing the identified cell so that a plant is generated.
 19. The method of claim 17, wherein the sequence of the target gene between the first and the second fragments differs from the sequence of the intervening region of the MDON at a mismatched nucleotide and the mutation of the target gene is located adjacent to the mismatched nucleotide.
 20. The method of claim 17, wherein the sequence of the target gene between the first and the second fragments differs from the sequence of the mutator segment of the MDON at a mismatched nucleotide and the mutation of the target gene is located at the mismatched nucleotide.
 21. The method of claim 17, wherein the target gene is a first ALS gene, a second ALS gene, a psbA gene, a threonine dehydratase gene, a dihydrodipicolinate synthase gene, or an S14/rp59 gene
 22. The method of claim 21, wherein the plant cell is a maize, wheat, rice or lettuce cell.
 23. The method of claim 21, wherein the plant cell is a potato, tomato, canola, soybean or cotton cell.
 24. The method of claim 17, wherein the target gene is selected from the group consisting of the genes encoding acid invertase, UDP-glucose pyrophosphorylase, polyphenol oxidase, O-methyl transferase, cinnamyl alcohol dehydrogenase, etr-1 or a homolog thereof, ACC synthase and ACC oxidase.
 25. The method of claim 24, where the target gene is a gene from a maize, wheat, rice or lettuce plant.
 26. The method of claim 24, where the target gene is a gene from a potato, tomato, canola, soybean or cotton plant.
 27. The method of claim 17, which further comprises making seeds from the plant or from progeny of the plant.
 28. A method of making a localized mutation in a target gene of a plastid of a plant cell which comprises the steps of: a. Introducing a recombinagenic oligonucleobase, which contains a first homologous region which has a sequence identical to the sequence of at least 6 base pairs of a first fragment of the target gene and a second homologous region which has a sequence identical to the sequence of at least 6 base pairs of a second fragment of the target gene, and an intervening region which contains at least 1 nucleobase heterologous to the target gene, which intervening region connects the first homologous region and the second homologous region; b. Identifying a cell having a mutation in the region between the first and second fragments of the target gene.
 29. The method of claim 28, wherein the recombinagenic oligonucleobase is a MDON and each of the homologous regions contains an RNA segment of at least 6 RNA-Type nucleotides.
 30. The method of claim 29, which further comprises culturing the identified cell so that a plant is generated.
 31. A method of making a localized, non-selectable mutation in a target gene in a plant cell comprising the steps of: a. introducing into the cells of a population of cells a mixture of a first recombinagenic oligonucleobase and a second reombinagenic oligonucleobase wherein: i. the first recombinagenic oligonucleobase contains a first homologous region which has a sequence identical to the sequence of at least 6 base pairs of a first fragment of a first target gene and a second homologous region which has a sequence identical to the sequence of at least 6 base pairs of a second fragment of the first target gene, and an intervening region which contains at least 1 nucleobase heterologous to the target gene, which intervening region connects the first homologous region and the second homologous region, and ii. the second recombinagenic oligonucleobase contains a first homologous region which has a sequence identical to the sequence of at least 6 base pairs of a first fragment of a second target gene and a second homologous region which has a sequence identical to the sequence of at least 6 base pairs of a second fragment of the second target gene, and an intervening region which contains at least 1 nucleobase heterologous to the target gene, which intervening region connects the first homologous region and the second homologous region; b. selecting cells from the population having a selectable mutation located between the first and the second fragments of the first target gene from the population; and c. identifying a selected cell having a non-selectable mutation located between the first fragment and the second fragment of the second target cell.
 32. The method of claim 31, wherein the each recombinagenic oligonucleobase is a MDON and each of the homologous regions contains an RNA segment of at least 6 RNA-Type nucleotides.
 33. The method of claim 32, wherein the first target gene is a first ALS gene, a second ALS gene, a psbA gene, a threonine dehydratase gene, a dihydrodipicolinate synthase gene, or an S14/rp59 gene.
 34. The method of claim 33, wherein the plant cell is a maize, wheat, rice or lettuce cell.
 35. The method of claim 33, wherein the plant cell is a potato, tomato, canola, soybean or cotton cell.
 36. The method of claim 32, wherein the second target gene is selected from the group consisting of the genes encoding acid invertase, UDP-glucose pyrophosphorylase, polyphenol oxidase, O-methyl transferase, cinnamyl alcohol dehydrogenase, etr-1 or a homolog thereof, ACC synthase and ACC oxidase.
 37. The method of claim 36, wherein the plant cell is a maize, wheat, rice or lettuce cell.
 38. The method of claim 36, wherein the plant cell is a potato, tomato, canola, soybean or cotton cell.
 39. The method of claim 32, which further comprises culturing the identified cell such that a plant is generated.
 40. The method of claim 39, which further comprises making seeds from the plant or from progeny of the plant.
 41. The method of claim 31, wherein the second recombinagenic oligonucleobase is a heteroduplex recombinagenic oligonucleobase and each of the homologous regions of the second recombinagenic oligonucleobase contains an RNA segment of at least 6 RNA-Type nucleotides.
 42. The method of claim 41, wherein the first target gene is a first ALS gene, a second ALS gene, a psbA gene, a threonine dehydratase gene, a dihydrodipicolinate synthase gene, or an S14/rp59 gene.
 43. The method of claim 42, wherein the plant cell is a maize, wheat, rice or lettuce cell.
 44. The method of claim 42, wherein the plant cell is a potato, tomato, canola, soybean or cotton cell.
 45. The method of claim 41, wherein the second target gene is selected from the group consisting of the genes encoding acid invertase, UDP-glucose pyrophosphorylase, polyphenol oxidase, O-methyl transferase, cinnamyl alcohol dehydrogenase, etr-1 or a homolog thereof, ACC synthase and ACC oxidase..
 46. The method of claim 36, 45, wherein the second target gene is from a maize, wheat, rice or lettuce plant.
 47. The method of claim 36, 45, wherein the second target gene is from a potato, tomato, canola, soybean or cotton plant.
 48. The method of claim 41, which further comprises culturing the identified cell such that a plant is generated.
 49. The method of claim 48, which further comprises making seeds from the plant or from progeny of the plant.
 50. A method of making a localized mutation in a target gene in a plant cell comprising the steps of: a. digesting a plant part with cellulase such that plant cell protoplasts are formed; b. suspending the protoplasts in a solution comprising a recombinagenic oligonucleobase which contains a first homologous region which has a sequence identical to the sequence of at least 6 base pairs of a first fragment of the target gene and a second homologous region which has a sequence identical to the sequence of at least 6 base pairs of a second fragment of the target gene, and an intervening region which contains at least 1 nucleobase heterologous to the target gene, which intervening region connects the first homologous region and the second homologous region; c. electroporating the suspension such that the recombinagenic oligonucleobase enters a protoplast of the suspension; d. culturing the protoplast; and e. identifying a progeny of the protoplast having a mutation located between the first and second fragments of the target gene.
 51. The method of claim 50, which further comprises the step of culturing the identified progeny such that a plant is generated.
 52. The method of claim 50, wherein the recombinagenic oligonucleobase is a MDON and each of the homologous regions contains an RNA segment of at least 6 RNA-Type nucleotides.
 53. The method of claim 50, wherein the recombinagenic oligonucleobase is an heteroduplex recombinagenic oligonucleobase.
 54. A plant or seed having a point mutation in a gene is in its wild type genetic position, which gene is selected from the group consisting of the genes encoding acid invertase, UDP-glucose pyrophosphorylase, polyphenol oxidase, O-methyl transferase, cinnamyl alcohol dehydrogenase, ACC synthase and ACC oxidase or etr-1 or a homolog of etr-1, and the sequence of the genomic DNA within 23 KB of the mutation is the sequence of the wild type DNA, and the point mutation forms a stop codon or is a frameshift mutation.
 55. The plant or seed of claim 54, in which the point mutation forms a stop codon.
 56. The plant or seed of claim 55, in which the sequence of the genomic DNA within 40 KB of the selectable mutation is the sequence of the wild type DNA.
 57. The plant or seed of claim 55, in which the sequence of the genomic DNA within 100 KB of the selectable mutation is the sequence of the wild type DNA.
 58. The plant or seed of claim 55, in which the point mutation is a single base pair mutation.
 59. The plant or seed of claim 55, which is a maize, wheat, rice or lettuce plant or seed.
 60. The plant or seed of claim 55, which is a potato, tomato, canola, soybean or cotton plant or seed.
 61. The plant or seed of claim 55, further having a selectable point mutation in a second gene and the sequence of the genomic DNA within 23 KB of the selectable point mutation is the sequence of the wild type DNA.
 62. The plant or seed of claim 61, in which the sequence of the genomic DNA within 40 KB of the selectable mutation is the sequence of the wild type DNA.
 63. The plant or seed of claim 61, in which the sequence of the genomic DNA within 100 KB of the selectable mutation is the sequence of the wild type DNA.
 64. The plant or seed of claim 54, in which the point mutation is a frameshift mutation.
 65. The plant or seed of claim 64, in which the sequence of the genomic DNA within 40 KB of the selectable mutation is the sequence of the wild type DNA.
 66. The plant or seed of claim 64, in which the sequence of the genomic DNA within 100 KB of the selectable mutation is the sequence of the wild type DNA.
 67. The plant or seed of claim 64, in which the point mutation is a single base pair mutation.
 68. The plant or seed of claim 64, which is a maize, wheat, rice or lettuce plant or seed.
 69. The plant or seed of claim 64, which is a potato, tomato, canola, soybean or cotton plant or seed.
 70. The plant or seed of claim 64, further having a selectable point mutation in a second gene and the sequence of the genomic DNA within 23 KB of the selectable point mutation is the sequence of the wild type DNA.
 71. The plant or seed of claim 70, in which the sequence of the genomic DNA within 40 KB of the selectable mutation is the sequence of the wild type DNA.
 72. The plant or seed of claim 70, in which the sequence of the genomic DNA within 100 KB of the selectable mutation is the sequence of the wild type DNA. 